Field of invention The present invention relates to novel heterocyclic compounds that may be useful as phosphodiesterase inhibitors (PDEs) in particular phosphodiesterase type 4 inhibitors represented by formula I, their derivatives, their analogs, their tautomeric forms, their stereoisomers, their bioisosters, their diastereomers, their polymorphs, their enantiomers, their appropriate N-oxides .their pharmaceutically acceptable salts , their pharmaceutically acceptable hydrates, their pharmaceutically acceptable solvates and pharmaceutically acceptable compositions containing them and their use in treating allergic and inflammatory diseases and for inhibiting the production of Tumor Necrosis Factor(TNF-a), Bacitground of the invention Bronchial asthma is a complex multifactorial disease characterized by hyperactivity of the respiratory tract to external stimuli. Airway inflammation leads to a number of severe lung diseases including Asthma and Chronic Obstructive Pulmonary Diseases (CORD, also known as Chronic Obstructive Airway Disease, Chronic Obstructive lung Disease or chronic airflow limitation and chronic airflow obstruction). The airflow limitation is usually progressive and associated with abnormal inflammatory response of the lungs to noxious particles or gases. Many biological responses are mediated by levels of cyclic nucleotides mainly cAMP and cGMP which in turn are synthesized by adenylyl cyclases (ACs) and guanylate cyclases (GCs). To regulate levels of cAMP and cGMP, all cells have Phosphodiesterases (PDEs) that hydrolyze cAMP and cGMP to 5'-AMP and 5'-GMP. In humans there are 21 different PDE isoforms that are classified into 11 different groups. Basically these PDEs fall into three categories lilce those that are specific to (i) cAMP, (ii) cGMP and (iii) those that act on both cAMP and cGMP. These 11 groups of PDEs are classified according to their nucleotide selectivity. PDE4 has 4 isoforms and in all these isoforms upstream conserved regions (UCRs) are present which appear to modulate dimerisation and may bind to signaling molecules such as lipids. There are atleast 18 different splice variants of the four PDE4 isoforms exist. Because of the critical role of cAMP in mediating cytokine responses cAMP specific PDE (PDE-4) play important role in the progression of inflammatory diseases. Many of the mediators of inflammatory response such as T cells, B cells, monocytes, neutrophils, eosinophils and macrophages have PDE4 enzymes as their primary cAMP specific PDE. Among the inflammatory diseases that are implicated by these cellular mediators are asthma, chronic obstructive pulmonary diseases (COPD), rheumatoid arthritis, inflammatory bowel disease, Crohn's disease and multiple sclerosis. Consequently the development of PDE4 inhibitors as therapeutic agents for these diseases has been a major pharmaceutical focus. PDE4 indirectly controls the degree of bronchodilation. In the inflammatory cells cAMP is a negative regulator of the primary activating pathways such as cytokine release by T-cells. Inhibition of the PDE4 isozymes in these cells results in elevated cAMP levels and consequent inactivation of the inflammatory response. In addition to the direct role of cAMP in inflammatory cell function, elevated cAMP levels also lead to smooth muscle relaxation. Consequently inhibition of PDE4 activity leading to fiigher cAMP levels cause bronchodilation thereby alleviating symptoms of respiratory diseases such as asthma or COPD. Also Inhibition of PDE4 enzyme increase levels of cAMP and Cyclic AMP modulates the activity of the most of the cells that contribute to the pathophysiology of allergic asthma. Elevation of cAMP would produce beneficial effects, some of which includes apart from airway smooth muscle relaxation, inhibition of mast cell mediator release, suppression of neutrophil degranulation, inhibition of basophil degranulation and inhibition of monocyte and macrophage activation. The connection between PDE4 activity and cognition has been speculated ever since the discovery that the cAMP -regulating dunce gene of the fruit fly encodes a PDE4 homo\ogue{Nature,1981,289,5793,79-1;J.mol.biol.,1991,222,3,553-565). Current drug discovery efforts involved the design of the PDE4 inhibitors with reduced side effects at the same time maintaining the anti inflammatory properties of rolipram. Compounds like Cilomilast, roflumilast, Lirimilast and AWD-12-281 belong to the second generation PDE4 inhibitors. One of the representative compounds is as given below and the compounds of invention claims for asthma and chronic obstructive pulmonary disease apart from other disease states. Challenges that are facing the PDE4 inhibitors are mainly nausea, vomiting, increased gastric acid secretion which may be because of selectivity towards binding sites. Based on the prior art reports compounds with selectivity for the high-affinity rolipram binding site causes side effects where as compounds with selectivity for low-affinity rolipram binding site are expected to have better therapeutic effects compared to rolipram (J. Biol. Chem. 1992,267(3):1798-1804: J. Biol. Chem. 1999,274(17):11796-11810). Other side effects include cardiac dysarhythmias, vasculitis and osteoporosis. As described above, as regulation of intracellular signaling is coordinated by PDE4, It has become a validated target for the development of therapeutics for inflammatory diseases such as asthma and COPD. PDE4 also has been shown to be a potential target for depression, memory enhancement, cardiovascular disease and osteogenesis. During the course of our research aimed at the development of novel anti-asthmatic compounds having potential PDE4 inhibitory activity, we have filed a WTO patent application in India bearing No. 1647/MUM/2006 dated September 11, 2006 and PCT application No PCT/IB2007/002596 dated September 10, 2007, 656/CHE/2008 dated March 14, 2008 are incorporated herein by reference in their entireties, for a novel series of heterocyclic compounds useful for the treatment of inflammatory and allergic disorders. Summary of the invention X represents O, S or NR"; Y represents 0, S, NR"* or can be absent; X^ and X^ independently represent hydrogen, hydroxy, amino, nitro, cyano and optionally substituted groups selected from all7 = 8.1 Hz), 10.2 (s, 1 H). Step-2: Preparation of Benzyl 4-(hydroxymethy!)-1H-indole-1-carboxylate The title compound was prepared following a similar procedure as described in step 2 of intermediate 1 and obtained as colorless viscous oil which solidified when stored in a refrigerator. IR (cm"^); 3304.58, 1732.37, 1528,8, 1486,06, 1433,27, 1399.51, 1347.57. 1275.50, 1128.54, 1051.71, 762.97. 'H NMR (300 MHz, CDCI3) 5 4.9 (s, 2 H), 5.4 (s, 2 H), 6.7 (dd, IN, J, = 0.6 Hz, J2 = 3.9 Hz), 7.2-7.35 (m, 2 H), 7,36-7.45 (m, 3 H), 7,46-7.5 (m, 2 H), 7.6 (d, 1 H, J= 3.6 Hz), 8.1 (d, ^H,J= 8.1 Hz). Step-3: Preparation of Benzyl 4-(chloromethyl)-1H-indo!e-1-carboxylate The title compound was prepared following a similar procedure as described in step 3 of intermediate 1 and obtained as a brown viscous mass. IR (cm"^): 3447, 1730.95, 1434.99, 1398.54, 1349.52, 1280,78, 1258.12, 1161.49, 1125.01, 1050.35, 762.09. ^H NMR (300 MHz, CDCI3) 5 4,8 (s, 2 H), 5,4 (s, 2 H), 6.7 (d, 1H, J = 3.9 Hz), 7.2-7,34 (m, 2 H), 7.36-7,5 (m, 5 H), 7.7 (d, 1 H, J = 3.9 Hz), 8.1 (d, 1 H, J = 7.8 Hz). Step-4: Preparation of Benzyl 4-(cyanomethyl)-1H-indole-1-carboxylate The title compound was prepared following a similar procedure as described in step 3 of intermediate 1 and obtained as an off-white solid. IR (cm"'): 3448.72, 2250.9, 1733.52, 1489.83, 1434.53, 1337.99, 1277.44, 1127,1, 1048.88, 975,39, 766.38, 752.16, 695.75. 'H NIVIR (300 MHz, CDCI3) 5 3.9 (s, 2 H), 5.4 (s, 2 H), 6.6 (d, 1H, J= 3.6 Hz), 7.2-7.37 (m, 3 H), 7.38-7.5 (m, 5 H), 7.7 (d, 1 H, J= 3.9 Hz), 8.1 (d, 1 H, J= 8,1 Hz), Intermediate 3: Preparation of (1- IVIethoxy-9-methyl-6-trifluoromethyl-9H-carbazole-4- yl)-acetonitrile The title compound was prepared according to the procedure depicted in WO 2006011024 andUS20050027129. IR (cm\ KBr) 3436, 2923, 2853, 2247, 1627, 1548, 1466, 1330, 1271, 1097, 795. 'H NMR (300 MHz, CDCI3) 8 4,0 (s, 3H), 4.22 (s, 3H), 4.29 (s, 2H), 6.90 (d, J = 8.1 Hz, 1H), 7.50 (m, 2H), 7.70 (d, J = 8.1 Hz, 1H), 8,24 (s, 1H), Intermediate 4: Preparation of (6-Fluoro-1-methoxy-9-metiiyl-9H-carbazol-4-yl)- acetonitrile Stepi: Preparation of 2-Hydroxymethyiene-cyclohexanone To a solution of cyclohexanone (25 g, 0.26 mole) in THF (1 litre) was added ethyl formate (25.48 g, 0.34 mole), and then 60% sodium hydride in paraffin oil (12.24 g, 0.31 mole) at 10- 20 "C and the mixture was stirred for overnight at room temperature. After completion of the reaction the reaction mixture was filtered and the solid was washed with dry tetrahydrofuram (200 ml), dried under vacuum to give the desired product (32.1 g, yield 100%) as off-white solid. 'H NMR (300 MHz, DMS0-d6): 6 1.40 - 1.56 (m, 4H), 1,86 -1,90 (m, 2H), 2.06-2.11 (m,2H), 9.18 (s, IN) Step 2: Preparation of 2-[(4-Fluoro-phenyl)-hydrazono]-cyclohexanone To the solution of 4-fluoroaniline (38 g, 0,34 mole) in water (300 ml) and cone, hydrochloric acid (71.3 ml, 0.68 mole), was added a solution of sodium nitrite (23.5 g, 0.34 mole) dissolved in water (80 ml) drop wise at 10 "C. The mixture was stirred for 30 min. at the same temperature and then a solution of compound of step 1 (43.09 g, 0,34 mole) in methanol (130 ml) followed by sodium acetate (70 g, 0.85 mole) and sodium carbonate (10.87 g, 0.10 mole) was added. The mixture was stirred for 30 minutes at room temperature. The mixture was extracted with dichioromethane (300 ml). The organic layer was dried over anhydrous sodium sulfate and concentrated under vacuum to afford the crude product which, on purification by column chromatography afforded the desired product (23 g, yield 30.7%) as orange colored solid. 'H NMR (300 MHz, CDCI3): 5 1.82 - 1,97 (m, 4H), 2.50 - 2.69 (m, 4H), 6.96 - 7,10 (m, 2H), 7.17 - 7.34 (m, 2H), 13, 82 (s, 1H) Step 3: Preparation of 6-Fluoro-2,3,4,9-tetrahydro-carbazol-1-one To the solution of compound of step 2 (23 g, 0,10 mole) in acetonitrile (600 ml) was added concentrated sulphuric acid (20 ml) and the mixture was refluxed for 2 hours. After completion of the reaction (indicated by TLC using 10% ethyl acetate / n-hexane as eluant), the mixture was diluted with water (750 ml) and stirred for 10 minutes, filtered and dried under vacuum to afford the title compound (21 g, yield 99.1%) as orange colored solid. ''H NMR (300 MHz, CDCI3): 8 2.26 - 2.33 (m, 2H), 2.67 (t, J = 6.1 Hz, 2H), 2.98 (t, J = 6.1 Hz, 2H), 7.11-7.18(171, 1H), 7.27-7.38 (m,2H), 8.74 (s, 1H) Step 4; Preparation of 6-Fluoro-9H-carbazol-1-ol To the solution of compound of step 3 (lOg, 0.05 mole) in diphenylether (1.2 I) was added 10% Pd/C (5g) and the mixture was refluxed for 5 hours. The mixture was then filtered, concentrated and the crude product was purified to afford the title compound (4g, yield 40.4%) as an off-white solid. ^H NMR (300 MHz, CDCI3): 5 6.85 (d, J = 7.6 Hz, 1H), 7.06 (t, J = 7.7Hz, 1H), 7.12-7.19 (m, 1H), 7.35-7.40 (m, 1H), 7.60 - 7.71 (m, IN) Step 5: Preparation of 6-Fluoro-1-methoxy-9-methyl-9H-carbazole To the solution of compound of step 4 (4.36 g, 0.02 mole) in dimethylformamide (50 ml), was added 60% sodium hydride in paraffin oil (2.08 g, 0.05 mole) at 0 "C and the mixture was stirred for 30 min. at 0 "C. Methyl iodide (3.36 ml, 0.05 mole) was added to this mixture and the reaction mass was stirred for 30 minutes at 0 °C. The mixture was quenched with water (250 ml) and extracted with dichloromethane (200 ml). The organic layer was collected, washed with water (5 X 100 ml), dried over anhydrous sodium sulfate and concentrated to give the desired product (4.2g, yield 84.7%) as off-white solid. ^H NMR (300 MHz, CDCI3): 5 3.96 (s, 3H), 4.08 (s, 3H), 6.85 (d, J = 7.7, 1H), 7.06 (t, J = 7.8 Hz, 1H), 7.12 - 7.24 (m, 2H), 7.56 (d, J = 7.7 Hz, 1H), 7.61 - 7.64 (m, 1H) Step 6: Preparation of 6-Fluoro-1-methoxy-9-methyl-9H-carbazole-4-carbaldehyde A solution of compound of step 5 (1.39 g, 0.01 mole) in DCM (50 ml) was cooled to 0 "C and titanium tetrachloride (1.38 ml, 0.01 mole) was added. The mixture was stirred for 10 min and then added dichloromethyl methyl ether (0.65 ml, 0.01 mole). After stirring for 30 min. at 0 "C (the starting material was absent by TLC) the mixture was treated with 20 % aqueous NaHCOs solution (100 ml) and extracted in dichloromethane (2 X 50 ml). The organic layers were collected, combined, dried over anhydrous sodium sulfate and concentrated to give a mixture of products (1.54 g) that was directly taken for the next step without purification. Step 7: Preparation of (6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl).methanol To the solution of compound of step 5 (1.54 g, 5.99 mmole) in THF (50 ml), was added sodium borohydride (360 mg, 9.51 mmole) portion wise at room temperature. After 2 hours stirring at room temperature (the starting material was absent by TLC) the reaction was diluted with water (100 ml). Extracted with ethyl acetate (2X50 ml), dried over anhydrous sodium sulfate and concentrated. The crude product was purified by column chromatography to afford the desired product (750 mg, yield 47.8% with respect to compound of 5) as a white solid. ^H NMR (300 MHz, DMSO-cfg): 6 3.95 (s, 3H), 4.13 (s, 3H), 4.92 (d, J = 5.2 Hz, 2H), 5.23 (s, 1H), 6.99 (d, J = 8.01 Hz, 1H), 7.07 (d, J = 7.99 Hz, 1H), 7.31 (m, 1H), 7.55 - 7.60 (m, 1H), 7.90 (dd, J =2.5 Hz, J =10.1 Hz, 1H) Step 8: Preparation of (6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-acetonitrile A solution of (6-fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-methanol (50 mg, 0.19 mmol) in ethyl acetate (5 ml) was cooled to -10 "C and thionyl chloride (0.02 ml, 0.23 mmol) was added drop wise. The reaction mass was stirred for 2 hours at the same temperature and then concentrated under vacuum. The residue was dissolved in DI\/1F (5 ml) and sodium cyanide (10 mg, 0.20 mmol) was added at room temperature. After 1 hour stirring at room temperature (the starting material was absent by TLC) the reaction mixture was quenched in water (5 ml) and extracted In ethyl acetate (2X5 ml). The combined organic layer was dried over anhydrous sodium sulfate and the solvent was evaporated in vacuum. The crude product was purified to afford the title compound (20 mg, yield 38.7%) as a white solid. ^H NMR (300 MHz, DMSO-c/«): 5 3,97 (s, 3H), 4.15 (s, 3H), 4.50 (s, 2H), 7.04 - 7.13 (m, 2H), 7.35-7.42 (m, 1H), 7.62-7.67 (m, 1H), 7.94 (dd, J= 10.0 and 2.4 Hz, 1H) IR (KBr) (cm-1): 3436, 2935, 2251, 1583, 1523, 1482, 1313, 1261, 1186, 1087, 1028, 887. Intermediate 5: Preparation of (1-Wlethoxy-9-methyl-9H-carbazol-4-yl)-acetonitrile Prepared this intermediate as per the procedure depicted in "Canadian journal of researcti (1950), 28B, 443-452". ^H NMR (300 MHz, CDCI3): S 3.99 (s, 3H), 4,18 (s, 3H), 4,24 (s, 2H), 6.89 (d, J = 8,1 Hz, 1H), 7.15 (d, J = 8.1 Hz, 1H), 7,27 (m, 1H), 7.43 - 7.54 (m, 2H), 8,01 (d, J=7.9H2, 1H) Intermediate 6: Preparation of 5-Cyano-5-(4-Cyclopentyloxy-8-nitro-dibenzofuran-1-yl)- 2-oxo-cyclohexane carboxylic acid methyl ester Step 1: Preparation of4-Cyclopentoxy-3-hydroxybenzaldehyde A suspension of 3, 4-dihydroxybenzaldehyde (5gms, 0.0362mol), anhydrous potassium carbonate (6gms, 0.0434mol) and cyclopentyl bromide (6.5gms, 0.0434mol) in dry dimethylformamlde DMF (50ml) was heated and stirred at 80°C for 24 hours. Reaction mixture was then cooled and diluted with water (500ml), acidified with IN HCI and extracted with ethyl acetate (3X100ml), The combined ethyl acetate layer was washed with 5% sodium bicarbonate and brine and dried on sodium sulfate, filtered and the solvent removed to get a residue which was purified by column chromatography on silica gel using 10% ethyl acetate in hexane as the eluentto obtain the title compound (5gms, yield-67,11%) as a white solid, ^H NMR (300 MHz, CDCI3) 8 1,62-2,06 (m, 8H), 4.90-4.95 (m, 1H), 5.73 (s, 1H), 6.95 (d, J = 8.2 Hz, 1H), 7.40-7.50 (m, 2H), 9,80 (s, 1H). Step 2; Preparation of 2-Bromo-4-cyclopentoxy-3-hydroxybenzaldehyde Compound of step 1 (18gm, 0.087mol) was dissolved in glacial acetic acid (540ml). Anhydrous sodium acetate (14.31gm, 0.174mol) was added to the above solution followed by powdered iron (396mg). The system was flushed thoroughly with nitrogen. A solution of bromine (5ml, 0.096mole) in glacial acetic acid (40ml) was added to the above stirred suspension at 16°C, over a period of 15 minutes. The reaction mixture was stirred at 15°C for 45 minutes. The reaction mixture was poured into aqueous 2% sodium bisulphate (500ml) solution and stirred for 10 minutes. The precipitated solid was filtered, washed with water (300ml) and dried to obtain the title compound (24gm, yield-96.1%) as a solid. ^H NMR (300 MHz, CDCI3) 5 1.61-2,03 (m, 8H), 4.91-4.97 (m, 1H), 6.07 (s, 1H), 6.89 {6, J = 8.6 Hz, 1H), 7.50 (d, J =8.6 Hz, 1H), 10.25 (s, 1H). Step 3: Preparation of 2-Bromo-4-cyclopentoxy-3-(4-nitrophonoxy) benzaldehyde To a stirred solution of compound of step 2 (26gm,0,091 moles) and potassium carbonate (31.5gm, 0.228mole) in dry dimethylformamide (260 ml) was added fluoronitrobenzene {10.16ml, 0.095mole) and then above reaction mixture was stirred at 140°C for 5 hours. After completion of reaction, the reaction mixture was cooled to room temperature and the contents were poured in to water (750ml) and extracted with ethyl acetate (3X500ml). The organic extracts were combined and washed with 1N aqueous sodium hydroxide solution, water and brine, dried with sodium sulfate, filtered and solvent evaporated under vacuum to obtain the title compound (32gm, yield-86%) a pale yellow solid. ^H NMR (300 MHz, CDCI3) 5 1.40-1.50 (m, 2H), 1.59-1.70 (m,4H), 1.73-1.80 (m,2H), 4.81- 4.85(m, 1H), 6.90-6.95 (m, 2H), 7.04 (d, J= 8.8 Hz, 1H), 7.90 (d, J= 8.8 Hz, 1H), 8.17-8.23 (m, 2H), 10.26 (s, 1H). Step 4: Preparation of 4-cyclopentoxy-8-nitro-1-formyl dibenzo [b, d] furan A solution of compound of step 3 (26.12gm, 0.064mol) in dimethylformamide (200ml), anhydrous sodium carbonate (20.45gm, 0.193mol) and Pd(ll) acetate (1.44gm, 0.006mol), were heated and stirred under nitrogen at 130°C for 7hours. After completion of reaction, the reaction mixture was filtered through celite bed, and then to the filtrate, water (500ml) was added and extracted with ethyl acetate (3X250ml). The combined organic layer was washed with 5% HCI (250ml), followed by water and dried with sodium sulfate, filtered and the solvent evaporated under vacuum to obtain the title compound (13.6gm, yield-65%) as a yellow color solid. ^H NMR (300 MHz, CDCI3) 5 1.60-1.79 (m, 2H), 1.80-1.99 (m, 4 H), 2.09-2.10 (m, 2H), 5.15 (m, 1H), 7.19(d, J =8.3 Hz, 1H), 7.74 (d, J = 9 Hz, 1H), 7.88 (d, J = 8.3, 1H), 8.46 (dd, J = 8.7Hz, 1.9Hz 1H), 10.02 (s, 1H), 10.17 (s, 1H). Step 5: Preparation of (4-Cyclopentyloxy-8-nitro-dibenzofuran-1-yl)-methanol To a cold solution of compound of step 4 (5gm, 0.015mole) in dry tetrahydrofuran (200ml) was added sodium borohydride (0.584gm, 0.015mole) portion wise at 0°C under nitrogen. The mixture was then allowed to stir at room temperature for 3 hours and then quenched with saturated solution of ammonium chloride (150ml). The mixture was extracted with ethyl acetate (3X150ml). The organic layer were collected, combined, dried over anhydrous sodium sulfate and concentrated under vacuum to obtain the title compound (3.5gm, yield- 69.5%) as a solid. 'H NMR (300 MHz, CDCI3) 5 1.57-1.73 (m, 2H), 1.89-1.99 (m, 4 H), 2.03-2.10 (m, 2H), 5.02- 5.16 (m, 1H), 5.16 (s, 2H), 7.04 (d, J = 8.2 Hz, 1H), 7.30 (d, J = 8.3 Hz, 1H), 7.73 (d, J = 9 Hz, 1H), 8,42 (dd, J= 9.0 Hz, 2.3 Hz, 1H), 9.08 (d, J= 2.2 Hz, 1H), Step 6: Preparation of (4-Cyclopentyloxy-8-nitro-dibenzofuran-1-yl)-acetonitrile To a cold solution of compound of step 5 (3.9gm, 0.011 mole) in dichloromethane (250 ml) was added thionyl chloride (1.74ml, 0.023mole) drop wise with stirring at 0°C under nitrogen atmosphere. The mixture was allowed to stir at room temperature for 2 hours. After completion of the reaction the solvent was evaporated completely under vacuum and the residue was dissolved in dry dimethylformamide (100ml). To this was added sodium cyanide (1.29gm, 0.026mole) portion wise and mixture was allowed to stir at room temperature for 18hours. After completion of the reaction, mixture was quenched with water (350ml) and extracted with ethyl acetate (3 X 200ml). The organic layer were collected, combined, dried over anhydrous sodium sulfate and concentrated under vacuum. The crude was purified by column chromatography by using 5-10% ethyl acetate-hexane as an eluent to obtain the title compound (3.59gm, yield-90 %) as a solid. ^H NMR (300 MHz, CDCI3) 5 1.57-1.73 (m, 2H), 1,85-1.96 (m, 2 H), 1.99-2.03 (m, 4H), 4.22 (s, 2H), 5.02-5.06 (m, 1H), 7.08 (d, J=B.3 Hz, 1H), 7.39 (d, J= 8.3, 1H), 7.78 (d, J= 9.1 Hz, 1H), 8.46 (dd,J= 9.1 Hz, 2.3Hz, 1H), 8.82 (d, J= 2.1 Hz, 1H), Step 7: Preparation of 4-Cyano-4-(4-Cyclopentyloxy-8-nitro-dibenzofuran-1-yl)- heptanedioic acid di methyl ester To a solution of compound of step 6 (2.4gm, 0.007moles) in acetonitrile (60ml) was added triton B (0.14ml) at room temperature. Reaction mixture was heated to reflux (85°C), at reflux temperature was added drop wise methyl acrylate (6.8ml, 0.071 mole) and then reaction was maintained at reflux for 5 hours. After completion of reaction, reaction mass was evaporated under vacuum. The crude was purified by column chromatography by using 5-10% ethyl acetate-hexane to obtain the title compound (5,69gm, yield-83.6 %) as a solid. ^H NMR (300 MHz, CDCI3) 6 1.71-1,75 (m, 2H), 1.89-1.94 (m, 2 H), 1.98-2.03 (m, 4H), 2.38- 2.43 (m, 2H), 2.54-2.67 (m, 4H), 2.78-2.83 (m, 2H), 3.57 (s, 6H), 5.01-5.04 (m, 1H), 7.06 (d, J =8.5 Hz, 1H), 7.47 (d, J = 8.5 Hz, 1H), 7.79 (d, J = 9.07 Hz, 1H), 8,46 (dd, J = 9.1 Hz, 1.9 Hz, 1H), 9.19(s, 1H) Step 8: Preparation of 5-Cyano-5-(4-Cyclopentyloxy-8-nitro-dibenzofuran-1-yl)-2-oxo- cyclohexane carboxyllc acid metliyi ester To a solution of sodium hydride (1.344gm, 0.0336mole) in dry dimethoxyethane (250ml) was added the compound of step 7 (5.69gm, 0.011 mole) in dimethoxyethane (25ml) by drop wise over a period of 20 minutes at room temperature under nitrogen. The mixture was then allowed to stir at room temperature for 2 hours and then quenched with saturated solution of ammonium chloride (200ml). The mixture was then extracted with ethyl acetate (3 X 250ml). The organic layers were collected, combined dried over anhydrous sodium sulfate and concentrated under vacuum to obtain the title compound (5.3gm, yield-98%) as a solid. ^H NMR (300 MHz, CDCI3) 6 1.64-1.76 (m, 2H), 1.85-1.96 (m, 2 H), 1.86-2.04 (m, 4H), 2.41- 2.63 (m, 2H), 2,63-2.69 (m, 1H), 2.92-2.97 (m, 2H), 3.45 (d, J = 16 Hz, IN), 3.83 (s, 3H), 5.01-5.07 (m, 1H), 7.06 (d, J=8.5Hz, 1H), 7.32 (d, J= 8.5 Hz, 1H), 7.79 (d, J= 9.1 Hz, 1H), 8.45 (dd, J= 9.1Hz, 2.1Hz, 1H), 9.19 (d, J= 2.1 Hz, 1H), 12.36 (s,1H) Intermediate 7: Preparation of 1-(-4-Hydroxy-8-nitro-dibenzofuran-1-yl)-4-oxo- cyclohexane carbonitrile Step 1: Preparation of 1-(-4-Cyclopentyloxy-8-nitro-dibenzofuran-1-yl)-4-oxo- cyclohexane carbonitrile To a solution of intermediate 1 (5.3gm, 0.011 mole) in dimethylsulphoxide (50ml), was added water(4ml), sodium chloride (4.2gm, 0.072mole) and then the reaction mass was heated to 140°C, and maintained at140°C for 5 hours. After completion of reaction, reaction mixture was brought to room temperature and quenclied witii cold water (150ml). The mixture was then extracted with ethyl acetate (3 X 250 ml). The organic layers were collected, combined dried over anhydrous sodium sulfate and concentrated under vacuum. The crude was purified by column chromatography by using 5-10% ethyl acetate-hexane to obtain the title compound (2.7gm, yield 58%) as a yellow color solid. ^H NMR (300 MHz. CDCI3) 5 1.70-1.79 (m, 2H), 1.89-1.93 (m, 2 H), 1.97-2.04 (m, 4H), 2.27- 2.37 (m, 2H), 2.70-2.75 (m, 2H), 2.97-2.98 (m, 2H), 3.02-3.21 (m, 2H), 5.02-5.06 (m, 1H), 7.08 (d, J = 8.5 Hz, 1H), 7.26-7.30 (m, 1H), 7.80 (d, J = 9.1 Hz, 1H), 8.47 (dd, J = 9.1Hz, 2.1Hz, 1H), 9.26(d, J=2.0, 1H) Step 2: Preparation of 1-(-4-Hydroxy-8-nitro-dibenzofuran-1-yl)-4-oxo-cyclohexane carbonitrile To a solution of step 1 (200mg, 0.0004mole) in glacial acetic acid (3ml), was added 33% HBr in acetic acid (1ml) at room temperature, and then reaction mixture was heated to 80°C and maintained at 80°C for 5 hours. After completion of reaction, the reaction mixture was quenched with ice cold water (10ml). The mixture was then extracted with ethyl acetate (3 X 50ml). The organic layers were collected, combined dried over anhydrous sodium sulfate and concentrated under vacuum to obtain the title compound (162 mg, yield 97%) as a solid. ^H NMR (300 MHz, DMSO-c/s) 5 2.40-2.57 (m, 6H), 2,89-2.92 (m, 2H), 7.15 (d, J = 8.5 Hz, 1H), 7.36 (d, J =8.5 Hz, 1H), 8.07 (d, J = 9.1Hz, 1H), 8.51 (dd, J=8.8, 1.6Hz, 1H), 9.13(d, J = 1.5 Hz, 1H), 10.87 (s, 1H) Intermediate 8: Preparation of 5-Cyano-5-(4-methoxy-8-trifluoromethyl-dibenzofuran-1- yl)-2-oxo-cyclohexanecarboxylic acid methyl ester Step-1: Preparation of 3-(2-Bromo-4-trifluoromethy!-plienoxy)-4-methoxy-benzaldehyde To a stirred solution of Isovanillin (5 gm, 0.0328 moles) and Potassium carbonate (13.6 gm, 0.0985 moles) in dry DMF (20 ml) was added 3-Bromo-4-Fluorobenzotrifluoride (8.065 gm, 0.0331 moles) over a period of 15 min at room temperature under nitrogen atmosphere, and then above reaction mixture was stirred at 140°C for 5 hrs. After completion of reaction, the reaction mixture was cooled to room temperature and the contents were poured in to water (100 ml) and extracted with ethyl acetate (3X100ml). The organic extracts were combined and washed with IN sodium hydroxide, water and brine, dhed with sodium sulfate, filtered and solvent evaporated under vacuum to obtain the title compound (11.58 gm, yield-94%) a pale yellow solid. 'H NMR (300 MHz, CDCI3) 8 3.92 (s, 3H), 6.75 (d, J = 8.6 Hz, 1H), 7.15 (d, J = 8.5 Hz, 1H), 7.45 (d, J= 8.6 Hz, 1H), 7.54 (d, J= 1.9 Hz, 1H), 7.77 (dd, J=8.4 Hz, J=1.9 Hz, 1H,), 7.90 (s, 1H), 9.87(s, 1H) MS(M*+1): 376 Step 2; Preparation of 4-Methoxy-8-trifluoromethyl-dibenzofuran-1-carbaldeliyde A solution of the step 1 (11.5 gm, 0.030 mol) in DMF (80 ml), anhydrous sodium carbonate (9.8 gm, 0.091 mol) and Pd(ll) acetate (0.689 gm, 0.0030 mol), were heated and stirred under nitrogen at 130°C for 7hrs. After completion of reaction RIVI was filtered througli celite bed, and then to the filtrate, water (500ml) was added and extracted with ethyl acetate (3X250ml). The combined organic layer was washed with water (250ml) and dried with sodium sulfate, filtered and the solvent evaporated under vacuum to obtain the title compound (4,5gm, yield-53.5 %) as a yellow color solid. ^H NMR (300 MHz, CDCI3) 6 4.18 (s, 3H), 7.18 (d, J = 8.4 Hz, 1H), 7.74 (d, J = 8.7 Hz, 1H), 7.82 (d, J =8.7 Hz, 1H), 7.88 (d, J =8.4 Hz, 1H), 9.41 (d, J= 1.8 Hz, 1H), 10.71 (s, 1H) MS(M'+1): 295.1 Step 3: Preparation of (4-Methoxy-8-trifluoromethyl-dibenzofuran-1-yl)--methanol To a cold solution of step 2 (4.5 gm, 0.015 moles) in dry THF (25 ml) was added sodium borohydride (0.640gm, 0.016 moles) portion wise at 0°C under nitrogen. The mixture was then allowed to stir at room temperature for 3 hrs and then quenched with saturated solution of ammonium chloride (50 ml). The mixture was extracted with Ethyl acetate (3X75 ml). The organic layer were collected, combined, dried over anhydrous sodium sulfate and concentrated under vacuum to obtain the title compound (4.3 gm, yield-94.9 %) as a solid. ^H NMR (300 MHz, CDCI3) 5 4.08 (s, 3H), 5.12 (s, 2H), 7.00 (d, J = 8.2 Hz, 1H), 7.28(d, J = 8.2 Hz, 1H), 7.70-7.77 (m, 2H), 8.43 (s, 1H) MS(M'+1):297 Step 4: Preparation of (4-Methoxy-8-trifluoromethyl-dibenzofuran-1-yl)--acetonitrile To a cold solution of step 3 (5.8 gm, 0.019 moles) in a 200 ml of dry DCM, thionyi chloride (2.86 ml, 0.039 moles) was added drop wise over a period of 15 min, under nitrogen atmosphere. After addition, reaction mixture was brought to room temperature and allowed to stir for 3 hrs. After completion of reaction, excess thionyi chloride and DCM was evaporated under vacuum completely. Here product is not isolated. To the non-isolated compound obtained above is added dry DMF (150 ml) and sodium cyanide (2.13 gm, 0.043 moles) at room temperature and reaction mixture allowed to stir for 2 hrs. After completion of reaction, RM was diluted with water (600 ml) and extracted with Ethyl acetate (3X500 ml). Combined organic layer was washed with water (500 ml), dried with sodium sulphate and concentrated under vacuum to obtain the title compound (5.7 gm, yield- 95.3%) as a yellow colored solid. ^H NMR (300 MHz, CDCI3) 6 4.09 (s, 3H), 4.20 (s, 2H), 7.06 (d, J = 8.3 Hz, 1H), 7.38 (d, J = 8.3 Hz, 1H), 7.75-7.82 (m, 2H), 8.17 (s, 1H) MS(M"+1):306 Step 5: Preparation of 4-Cyano-4-(4-Methoxy-8-trifluoromethyl-dibenzofuran-1-yl) hepatanedioic acid dimethylester To a solution of step 4 (2.7gm, 0.0088 moles) in acetonitrile (20 ml) was added Triton B (0.8 ml, 0.004 moles) at room temperature, reaction mixture was heated to reflux (85°C), at reflux temperature was added drop wise Methyl acrylate (8.45 ml, 0.088 moles) and then reaction was maintained at reflux for 5 hrs. After completion of the reaction, the reaction mass was evaporated under vacuum. The crude was purified by column chromatography by using 5- 10% Ethyl acetate-Hexane to obtain the title compound (2.53 gm, yield-60 %) as a Pale yellow solid. 'H NMR (300 MHz, CDCI3) 5 2,40-2.56 (m, 2H), 2.58-2.66 (m, 4H), 2.76-2.82 (m, 2H), 3.63 (s, 6H), 4.09 (s, 3H), 7.05 (d, J = 8.6, 1H), 7.50 (d, J = 8.6 Hz, 1H), 7.79-7.80 (m, 2H), 8.51 (s, 1H) MS(M''+1):478 Step 6: Preparation of 5-Cyano-5-(4-methoxy-8-trifluoromethyl-dibenzofuran-1-yl)-2- oxo-cyclohexanecarboxylic acid methyl ester To a solution of sodium hydride (1.56 gm, 0.032 moles) in dry DME (50 ml) was added drop wise step 5 (5.20 gm, 0.010 moles) by dissolving it in DME (50 ml) over a period of 20 min at room temperature under nitrogen. The mixture was then allowed to stir at room temperature for 2 hrs and then quenched with saturated solution of ammonium chloride (100 ml). The mixture was then extracted with ethyl acetate (3 X 250 ml). The organic layers were collected, combined dried over anhydrous sodium sulfate and concentrated under vacuum to obtain the title compound (3.4 gm, yield-65.8 %) as a Yellow solid. ^H NMR (300 MHz, CDCI3) 5 2.40-2.67 (m, 3H), 2.84-2.89 (m, 2H), 3.50 (d, J = 16.6 Hz, 1H), 3.80 (s, 3H), 4.10 (s, 3H), 7.05 (d, J = 8.5 Hz, 1H), 7.32 (d, J = 8,5 Hz, 1H), 7.79 (m, 2H), 8.51 (s, 1H), 12,34(3, 1H) MS(M^+1):446 Intermediate 9: Preparation of 3-Dimethylaminomethylene-1-(4-methoxy-8- trifluoromethyl-dibenzofuran-1-yl)-4-oxo-cyclohexanecarbonitrile Step 1: Preparation of 1-(4-Methoxy-8-trifluoromethyl-dibenzofuran-1-yl)-4-oxo- cyclohexane-caronitrile To a solution of Intermediate 8 (3,4 gm, 0.0076 moles) in dimethyl sulphoxide (DMSO)(10 ml), was added water(1 ml), sodium chloride (2,9 gm, 0.049 moles) and then the reaction mass was heated to 140°C, and maintained atl40°C for 5 hours. After completion of reaction, reaction mixture was brought to room temperature and quenched with cold water (50 ml). The mixture was then extracted with ethyl acetate (3 X 75 ml). The organic layers were collected, combined dried over anhydrous sodium sulfate and concentrated under vacuum. The crude was purified by column chromatography by using 5-10% ethyl acetate- hexane to obtain the title compound (1,9 gm, yield 65 %) as a yellow color solid. Step 2: Preparation of 3-dimethylaminomethylene-1-(4-methoxy-8-trifluoromethyl- dibenzofuran-1-yl)-4-oxo-cyclohexanecarbonitrile A solution of step 1 (0.400g, 0.0010 moles) in Benzene (10 ml) and 2 drops of triethylamine was added DMFDMA (0,2 ml, 0.0016 moles) at room temperature under nitrogen. Reaction mixture was heated to 110°C. Removed Benzene by Dean and Stark apparatus and added fresh Benzene (10 ml) 3 to 4 times, this process was continued for 6 hours. After completion of reaction, reaction mass was evaporated under vacuum to obtain the title compound as a brown color residue (0.411 gm), which, is further used as such without purification. Step-1: Preparation of Benzyl-4-(1,5-dimethoxycarbonyl-3-cyanopentan-3-yl)-1H-indole-1-carboxylate To a solution of intermediate 2 (2.3 g, 7.93 mmol) in DIViSO (20 ml) was added 1,1,3,3- tetramethyl guanidine (0.5 ml, 3.96 mmol) and methyl acrylate (7.1 ml, 79.3 mmol) at 10-15 °C and the mixture was stirred at room temperature for about one and half hours. The mixture was cooled to ICC, diluted with water and extracted with ethyl acetate. The organic layers were collected, combined, washed with water followed by brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The crude product was purified by column chromatography to afford the title compound (3,3 g, 90,65 %) as a white solid. IR (cm"'): 3445.15, 2956.39, 2237.09, 1744.64, 1730.68, 1426,84, 1395.78, 1345.64, 1279.23, 1252.46, 1215.28, 1132,97, 1053.04, 762.35. 'H NMR (300 MHz, CDCI3) 5 2.09-2.14 (m, 2 H), 2.42-2.55 (m, 4 H), 2.59-265 (m, 2 H), 3,57 (s, 6 H), 5.4 (s, 2 H), 6.8 (d, 1H, J = 3.6 Hz), 7.3-7.49 (m, 7H), 7.7 (d, 1 H, J = 3,9 Hz), 8.2 (d, 1 H, J=8.1 Hz). Step-2: Preparation of Methyl 5-cyano-5-(1H-indol-4-yl)-2-oxocyclohexanecarboxylate To a solution of compound of step 1 (2.8 g, 6.08 mmol) in 1,2-dimethoxyethane (DME, 65 ml) was added sodium hydride (876 mg, 18.24 mmol, 55%) portion wise in 30 minutes at 0 "C and the mixture was stirred at the same temperature for 2 hours. The mixture was quenched with saturated ammonium chloride solution and extracted with ethyl acetate. The organic layers were collected, combined, washed with brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The crude product was purified by silica gel column chromatography using 10% ethyl acetate-hexane to afford the title compound (2.6 g, 70 %) as white solid. IR (cm"'); 3340.72, 2233.31, 1662.58, 1606.62, 1444.29, 1339.79, 1292.94, 1222.10, 1100.67,787.24,754.21. 'H NMR (300 MHz, CDCI3) 5 1.23-1.34 (m, 1 H), 2.42-2.51 (m, 3 H), 2.82-2.93 (m, 2 H), 3.2 (br d, 1 H. J = 16.2 Hz), 3.78 (s, 3 H), 6.8 (br s, 1 H), 7.1-7.3 (m, 3 H), 7.4 (d, 1 H, J = 7.4 Hz),8,3(brs, 1 H), Step-3: Preparation of 1.(1H-lndol-4-yl)-4-oxoGyciohexanecarbonitrile To a solution of compound of step 2 (5,9 g, 19.9 mmol) in dimethyl sulfoxide (80 ml) was added H2O (10.8 ml) followed by sodium chloride (7.5 g, 129.3 mmol) at room temperature and the mixture was stirred at 145-150 "C for 5 hours. The mixture was cooled to room temperature, diluted with water and extracted with ethyl acetate (3 x 100 ml). The organic layers were collected, combined, washed with water followed by brine, dried over anhydrous sodium sulfate and concentrated under vacuum to afford the title compound (3.0g, 63.8 %) as off-white solid. IR (cm"^): 3274,67, 2230.30, 1707.40, 1413.71, 1359.89, 1338.74, 1286.54, 901.29, 750.46. 'H NMR (300 MHz, CDCI3) 5 2.5 (m, 4 H), 2.64-2.85 (m, 4 H), 6.7 (s, 1 H), 7.1 (m, 2 H), 7.5 (m, 2H), 11.3 (brs, 1 H). Step-4: Preparation of 1-(1-Methyl-1H-indol-4-yl)-4-oxocyclohexanecarbonitrile To a solution of compound of step 3 (200 mg, 0.84 mmol) in N,N-dimethyi formamide (2 ml) was added cesium carbonate (415 mg, 1.27 mmol) at room temperature followed by methyl iodide (71 pi, 1.09 mmol) and the mixture was stirred for one and half hours. The reaction mass was diluted with water and extracted with ethyl acetate (3 x 20 ml). The organic layers were collected, combined, washed with water followed by brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The crude product was crystallized from 30% ethyl acetate-hexane to afford the title compound (180 mg, 85 %) as off-white solid. IR (cm"^): 3412.94, 2951.96, 2232.62, 1720.33, 1514.44, 1426.02, 1338,62, 1293.37, 1249.31, 1221.03,754.27. ^H NMR (300 MHz, CDCI3) 6 2.4-2.49 (m, 4 H), 2.64-2.80 (m, 4 H), 3.8 (s, 3 H), 6.7 (d, 1 H, J = 3.3 Hz), 7.1 (m, 2 H), 7.5 (m, 2 H). MS m/z [M+1] 253.0, [M+Na] 275.0. Step-5: Preparation of 4,5,6,7-Tetrahydro-5-(1-methyl-1H-indol-4-yl)-2H-indazole- 5- carbonitrile To a solution of compound of step 4 (500 mg, 1.98 mmol) in N, N- dimethylformamide (8 ml) was added N,N- dimethylformamide dimethylacetal (DMFDMA) (0.5 ml, 3.96 mmol) and the mixture was stirred for 1 hour at 110-120 "C under a nitrogen atmosphere. The reaction mixture was cooled to room temperature, diluted with water and extracted with ethyl acetate. The organic layers were collected, combined, washed with water followed by brine, dried over anhydrous sodium sulfate and concentrated under vacuum to afford the crude enamine intermediate (600 mg) as a brown solid which was dissolved in ethanol (8 ml). To this solution was added hydrazine hydrate (117 mg, 2.34 mmol) and the mixture was stirred at room temperature for 1 hour. The mixture was diluted with water and extracted with ethyl acetate (3 x 50 ml). The organic layers were collected, combined, washed with water followed by brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The crude product was purified by column chromatography using silica gel, eluted with 1% MeOH-CHCIa to give title compound (130 mg, 24 %) as yellow color powder, mp: 203-205 "C. IR (cm"^): 3269.97, 2926.79, 2854.56, 2231.14, 1606.77, 1515.83, 1498.26, 1436.46, 1340.98, 1298.22,749.93. 'H NMR (300 MHz, CDCI3) 6 2.69-2.62 (m, 2 H), 2.89-2.80 (m, 1 H), 3.14-3.09 (m, 1 H), 3.53-3.3 (ABq, J, = 15.9 Hz, Jj = 46,5 Hz, 2 H), 3.8 (s, 3 H), 6.8 (dd, J, = 0.6 Hz, J2 = 3.3 Hz, 1H), 7,3 (m, 1H), 7.1 (m, 3H), 7.4 (brs, 1H). Example 2 step 1: Preparation of 4,5,6,7-Tetrahydro-5-(1H-indol-4-yl)-2H-indazole-5-carbonitrile To a solution of 1-(1H-indol-4-yl)-4-oxocyclohexanecarbonitrile (400 mg, 1.68 mmol) in N,N-dimethylformamide (6 ml) was added N, N- dimethylformamide dimethylacetal (DMFDMA, 447 pi, 3.36 mmol) and the mixture was stirred for 1 hour at 110-120 "C under nitrogen atmosphere. The mixture was cooled to room temperature, diluted with water and extracted with ethyl acetate (3 x 50 ml). The combined organic layers were washed with water followed by brine, dried over anhydrous sodium sulphate and concentrated under vacuum to afford crude enamine intermediate (400 mg) as a brown solid which was suspended in ethanoi (4 ml). To this solution was added hydrazine hydrate (62 [JI, 1.22 mmol) and the mixture was stirred at 55-60 °C for about 30 minutes. The reaction mixture was diluted with water and extracted with ethyl acetate (3 x 50 ml). The combined organic layers were washed with water followed by brine, dried over anhydrous sodium sulphate and concentrated under vacuum. The crude product was purified column chromatography to obtain the title compound (140 mg, 31.8 %) as a yellow color powder, mp: 133-135 °C. IR (cm"^); 3409.36, 2929.77, 2234,44, 1613.45, 1505.56, 1436.24, 1413.35, 1339.77, 1088.57,753.44. 'H NMR (300 MHz, CDCI3 + CD3OD) 5 2.7-2.65 (m, 1H), 2.92-2.83 (m, 1H), 3.15-3.07 (m, 1 H), 3.5-3.3 (ABq, J, = 15.6 Hz, J^ = 39.9 Hz, 2H), 6.8 (m, 1H), 7.1 (m, 2H), 7.3 (m, 1H), 7.4 (m, 1H). Step-1: Preparation of Dimethyl 4-cyano-4-(7-methoxy-1-tosyl-1H-indol-4-yl)heptanedioate The title compound was prepared using intermediate 1, following a similar procedure as mentioned in step 1 of example 1 as a white solid. IR (cm"^): 3448.03, 2956.11, 2231.92, 1746.74, 1732.08, 1375.38, 1175.94, 1144.57, 614.79. ^H NMR (300 MHz, CDCia) 5 2.11-2.15 (m, 2 H), 2.38-2.61 (m, 6 H), 2.4 (s, 3 H), 3.5 (s, 6 H), 3.6 (s, 3 H), 6.6 (d, 1 H, J = 8.4 Hz), 6.8 (d, 1 H, J = 3.9 Hz), 7.2-7.31 (m, 3 H), 7.7 (d, 2 H, J = 8.4 Hz), 7.9 (d, 1 H, J=3.9Hz). Step-2: Preparation of Methyl-5-cyano-5-(7-methoxy-1-tosyl-1H-indol-4-yl)-2- oxocyclohexanecarboxylate The title compound was prepared following a similar procedure as mentioned in step 2 of example 1 as a white solid. IR (cm"^): 3435.65, 2942.38, 2230.13, 1665.21, 1626.06, 1497.05, 1443.15, 1357.18, 1291.32,667.91. 'H NMR (300 MHz, CDCI3) B 1.2 (m, 1 H), 2.35-2.47 (m, 3 H), 2.4 (s, 3 H), 2.75-2.9 (m, 2 H), 3.2 (br d, 1 H, J = 16.5 Hz), 3.7 (s, 3 H), 3.8 (s, 3 H), 6.6 (d, 1 H, J = 8.4 Hz), 7.0 (d, 1 H, J = 3.9 Hz), 7.1 (d, 1 H, J = 8.4 Hz), 7.3 (d, 1 H, J = 8.4 Hz), 7.7 (d, 1 H, J = 8.4 Hz), 7.9 (d, 1 H, J =3.6 Hz); Step-3: Preparation of 1-(7-Methoxy-1-tosyl-1H-indol-4-yl)-4-oxocyclohexane- carbonitrjle The title compound was prepared following a similar procedure as mentioned in step 3 of example 1 as an off-white solid. IR (cm"^): 2961.70, 2941.17, 2234.16, 1716.99, 1495.36, 1373.4, 1357.62, 1289.51, 1244.53, 1170.21, 1143.32, 680.67, 657.14. 'H NMR (300 MHz, CDCis) 5 2.33-2.33 (m, 2 H), 2.4 (s, 3 H), 2.57-2.62 (m, 2 H), 2.69-2.76 (m, 2 H), 2.92-3.0 (m, 2 H), 3.68 (s, 3 H), 6.6 (d, 1 H, J= 8.4 Hz), 7.0 (d, 1 H, J =2.9 Hz), 7.1 (d, 1 H, J=8A Hz), 7,3 (d, 1 H, J= 8,1 Hz), 7.7 (d, 1 H, J= 8.1 Hz), 7.9 (d, 1 H, w/= 3,9 Hz); Step-4: Preparation of 4,5,6,7-Tetrahydro-5-(7-methoxy-1 -tosyl-1 H-indol-4-yl)-2H- indazole-S-carbonitrile The title compound was prepared following a similar procedure as mentioned in step 5 of example 1 as an off-white solid. IR (cm"^): 3391.79, 2930,43, 2853.94, 2233.13, 1584.29, 1373.5, 1357.76, 1289,75, 1243.49, 1171.56, 1141.53, 1087.17, 681.01, 664.95. 'H NMR (300 MHz, CDCI3) 5 2.4 (s, 3 H), 2.51- 2,57 (m, 2 H), 2.8 (m, 1 H), 3.1 (m, 1 H), 3.4 (m, 2 H), 3.67 (s, 3 H), 6.6 (d, 1 H, J = 8.4 Hz), 7,0 (d,1 H, J =3.9 Hz), 7.1 (d, 1 H, J = 8.7 Hz), 7.3 (d, 2 H, J = 8.4 Hz), 7.4 (s, 1 H), 7.7 (d, 2 H, J = 8.1 Hz), 7.9 (d, ^H.J= 3.9 Hz); Step-5: Preparation of 4,5,6,7-Tetrahydro-5-(7-methoxy-1H-indol-4-yl)-2H-indazole-5 - carbonitrile To a solution of compound of step 4 (420 mg, 0.94 mmol) in 35% dichlomethane-methanol (30 ml) was added Mg (226 mg, 9.4 mmol) at room temperature and the mixture was stirred at the same temperature for 4 hours. The mixture was treated with saturated ammonium chloride solution at 10 "C, filtered through celite bed and washed with dichlomethane. From the filtrate, dichioromethane layer was separated and aqueous layer was extracted with dichlomethane (2 x 30 ml). The organic layers were collected, combined, washed with water followed by brine, dried over anhydrous sodium sulphate and concentrated under vacuum. The crude product was purified by silica gel column chromatography using 1% MeOH-CHCIs to give the title compound (140 mg, 51 %) as off-white solid. HPLC purity: 98.57 %. IR (cm''): 3402.04 (br), 2933.13, 2853.80, 2233.68 (CN), 1626.04, 1577.44, 1524.58, 1500.90, 1444.59, 1417.95, 1347.55, 1278.47, 1083.61, 960.59. 'H NMR (300 MHz, CDCI3) 6 2.65-2.59 (m, 2H), 2.88-2.80 (m, 1H), 3.13-3.08 (m, 1H), 3.49-3.29 (ABq, 2H, J, = 43.65 Step-1: Preparation of Dimethyl 4-cyano-4-(7-methoxy-1-tosyl-1H-indol-4-yl) heptanedioate The title compound was prepared using intermediate 1, following a similar procedure as mentioned in step 1 of example 1 as a white solid. IR (cm"^): 3448.03, 2956.11, 2231.92, 1746.74, 1732,08, 1375.38, 1175.94, 1144,57, 614,79. 'H NMR (300 MHz, CDCI3) 6 2.11-2.15 (m, 2 H), 2.38-2.61 (m, 6 H), 2.4 (s, 3 H), 3.5 (s, 6 H), 3.6 (s, 3 H), 6.6 (d, 1 H, J = 8.4 Hz), 6.8 (d, 1 H, J = 3.9 Hz), 7.2-7.31 (m, 3 H), 7.7 (d, 2 H, J = 8.4 Hz), 7.9 (d, 1 H, J=3.9Hz). Step-2: Preparation of Dimethyl 4-cyano-4-(7-methoxyl-1H-indol-4-yl)- heptanedioate The title compound was prepared following a similar procedure as mentioned in step 5 of example 3 as a white solid (120 mg, 22 %). IR (cm"'): 3436.07, 3103.20, 2963.32, 2933.75, 2898.64, 2244.88, 1731.64, 1581,64, 1524.82, 1507,82, 1259,84, 'H NMR (300 MHz, DMSO-dg) 5 3.8 (s, 3 H), 4.0 (s, 3 H), 4.05 (s, 2H), 6.4 (br s, 1 H), 6.6 (d, J = 7.8 Hz, 1 H), 6.9 (d, J = 7.5 Hz, 1 H), 7.2 (br s, 1 H). Step-3: Preparation of Dimethyl 4-cyano-4-(7-methoxy-1-methyl-1H-indol-4-yl) heptanedioate To a solution of compound of step 2 (3.0 g, 8.37 mmol) in N,N-dimethylformamide (25 ml) was added powdered sodium hydroxide (161 mg, 4.02 mmol) at 0 "C followed by methyl iodide (0.8 ml, 12.56 mmol). The mixture was then stirred for 2 hours at the same temperature, quenched with acetic acid, diluted with water and extracted with ethyl acetate (3 x 50 ml). The organic layers were collected, combined, washed with water followed by brine, dried over anhydrous sodium sulfate and concentrated under vacuum to afford the title compound (2.7 g, 86.8 %) as off- white solid. IR (cm"'): 3450.81, 2953.16, 2235.44, 1737.52, 1576.54, 1508.19, 1437.68, 1296.44, 1270.73, 1199.09, 1175.75, 1093, 31, 727.90. 'H NMR (300 MHz, CDCI3) 6 2.1 (m, 2 H), 2.3-2.6 (m, 4H), 2.65-2.8 (m, 2 H), 3.6 (s, 6 H), 3.9 (s, 3 H), 4.06 (s, 3 H), 6.5 (m, 2 H), 6.9 (d, 1 H, J= 3.0 Hz), 7.1 (d, 1 H, J= 8.1 Hz); Step-4: Preparation of Methyl-5-cyano-5-(7-methoxy-1-methyl-1H-lndol-4-yl)-2-oxocyclo- hexane-carboxylate The title compound was prepared following a similar procedure as mentioned in step 2 of example 1 as a white solid. IR (cm'V 2959.37, 2937.38, 2224,81, 1663.22, 1612,39, 1505,02, 1443,63, 1294.83, 1273.84, 1215.83, 1091.48, 798.18. ^H NMR (300 MHz, CDCI3) 5 1.25 (m, 1 H), 2.38-2.46 (m, 3 H), 2.78-2.94 (m, 2 H), 3.2 (br d, 1 H, J= 16.2 Hz), 3.7 (s, 3 H), 3,9 (s, 3 H), 4,06 (s, 3 H), 6,5 (d, 1 H, J=8,1 Hz), 6,7 (d, 1 H, J = 3,3 Hz), 6.9 (d, 1 H, J=8,1 Hz), 7.0 (d, 1 H, J =3.0 Hz). Step-5: Preparation of 1-(7-Methoxy-1-methyl-1H-indol-4-yl)-4-oxocyclohexanG- carbonJtrile The title compound was prepared following a similar procedure as mentioned in step 3 of example 1 as an off-white solid. IR (cm"^): 3401.32, 2938,10, 2907.83, 2840,92, 2233.14, 1717.58, 1572.80, 1505.01, 1467.86, 1429.99, 1292,68, 1272.11. ^H NIVIR (300 MHz, CDCI3) 5 2.42-2,32 (m, 2H), 2.61-2.55 (m, 2H), 2.81-2.74 (m, 2H), 3.05- 2,93 (m,2H), 3,9 (s, 3H), 4.07 (s, 3H), 6.5 (d, 1H, >y=8.1 Hz), 6,7 (d, 1H, J= 3.0 Hz), 6,9 (d, 1H, J=8.1 Hz), 7.0(d, 1H, J = 3.3Hz). Preparation of 4,5,6,7-Tetrahydro-5-(7-methoxy-1 -methyl-1 H-inciol-4-yI)-2H-indazole-5-carbonitrile The title compound was prepared following a similar procedure as mentioned in step 5 of example 1 as a yellow color powder (160 mg, 30 %), IR (cm'^): 3167.49, 2933,22, 2231,81 (CN), 1733.66, 1610.72, 1575.06, 1507.03, 1400.47, 1359,44, 1297.85, 1269.42, 1103,24, 964.04, 794,87, ^H NMR (300 MHz, CDCI3) 5 2,63-2.58 (m, 2H), 2.86-2.77 (m, 1H), 3.14-3.06 (m, 1H), 3.49-3.26 (ABq, 2H, Ji = 52,05 Hz, J2 = 15.9 Hz), 3.92 (s, 3H), 4,0 (s, 3H), 6.5 (d, 1H, J = 8.1 Hz), 6.7 (d, 1H, J = 3,3 Hz), 7.4 (s, 1H), 7.0(m, 2H). Step 1: Preparation of 4-hydroxy-1-(7-methoxy-1H-indol-4-yl)-cyclohexanecarbonitrile The title compound was prepared by using the compound prepared in step 3 of example 3 and following a similar procedure as mentioned in step 5 of example 3. Step 2: Preparation of 1-(7-methoxy-1H-indol-4-yl)-4-oxocyclohexanecarbonitrile To a solution of compound of step 1 (400 mg, 1.48 mmol) in dichlorometiiane (10 ml) was added pyridinium chlorochromate (PCC) (638 mg, 2.96 mmol) at 0 "C and the mixture was stirred at room temperature for 2 iiours. The reaction mixture was diluted with dichloromethane and filtered through celite. The filtrate was concentrated under vacuum and the crude product was purified by column chromatography using silica gel eluted with 15 % ethyl acetate-hexane to give the title compound (168 mg, 42.8 %) as off-white powder. IR (cmV 3380.22, 2949.13, 2925.66, 2236.84, 1708.08, 1574.66, 1523.93, 1504.73, 1273.55741.80. ^H NMR (300 IVIHz, CDCI3) 5 2.47-2,36 (m, 2H), 2.63-2.56 (m, 2H), 2.80-2.73 (m, 2H), 3.06-2.94 (m, 2H), 3.9 (s, 3H), 6,59 (d, 1H, J = 8,1 Hz), 6.8 (dd, 1H, J, = 3.15 Hz, J2=2.1 Hz), 7.0 (d, 1H, J = 8,1 Hz), 7.2 (t, 1H, J = 2.8 Hz), 8.58 (br s, 1H, NH). Example 7 Step 1: Preparation of 4-(6-Fluoro-1-methoxy-9-methyl-9H-carba20l-4-yl)-heptanedioic acid dimethyl ester The title compound was prepared using the intermediate 4, according to a similar procedure mentioned in step 1 of example 1. In this example we used triton B as a base instead of 1,1,3,3-tetramethyl guanidine under reflux. ^H NMR (300 MHz, DMSO-c/g): 6 2,4 - 2.8 (m, 8H), 3,50 (s, 6H), 3.99 (s, 3H), 4,20 (s, 3H), 7.09 - 7,17 (m,2H), 7.40-7.46 (m, 1H), 7.7-7.74 (m, 1H), 8.05 (d, J= 10.7 Hz, 1H), Step2: Preparation of 5-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-2-oxo cyclohexanecarboxylic acid methyl ester The title compound was prepared following a similar procedure mentioned in step 2 of example 1 at room temperature instead of 0 "C. 'H NMR (300 MHz, DMSO-cys): 6 2.64 - 2.90 (m, 4H), 3,20 - 3.5 5 (m, 2H), 3.76 (s, 3H), 3,99 (s, 3H), 4.21 (s, 3H), 7.1-7.20 (m,2H), 7.40-7.50 (m, 1H), 7.7 - 7.79 (m, 1H), 7.89 (d, J = 9.2 Hz, 1H), 12,14 (s, 1H). Step 3: Preparation of 4-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-cyclohexanone The title compound was prepared following a similar procedure mentioned in step 3 of example 1. IR (KBr) (cm y. 3436, 2951, 2720, 2221, 1727, 1581, 1486, 1317, 1272, 1240, 1194, 905, 802. 'H NMR (300 MHz, CDCI3): 8 2.24 - 2.34 (m, 2H), 2.65 - 2.71 (m, 2H), 3.07 - 3.15 (m, 4H), 4.01 (s, 3H), 4,22 (s, 3H), 6.90 (d, J= 8.4 Hz, 1H), 7.07 (d, J= 8,4 Hz, 1H), 7.26-7.32 (m, 1H), 7.39 - 7.44 (m, 1H), 8.08 (d, J = 9.2 Hz, 1H). Example 8 step 1: Preparation of 4-{1-methoxy-9-methyl-9H-carbazol-4-yl)-hGptanedioic acid dimethyl ester The title compound was prepared using the intermediate 5, according to the procedure mentioned in step 1 of example 1. In this example we used triton B as a base instead of 1,1,3,3-tetramethyl guanidine under reflux. 'H NMR (300 IVIHz, CD3OD): 5 2.2 - 2.8 (m, 8H), 4.02 (s, 6H), 4.22 (s, 3H, s), 4.57 (s, 3H), 7.03 (d, J = 8.3 Hz, 1H), 7.24 - 7.34 (m, 2H), 7.47 - 7.58 (m, 2H), 8.33 (d, J = 7.7 Hz, 1H) Step2: Preparation of 5-(1-methoxy-9-methyl-9H-carbazoM-yl)-2-oxocyclohexane carboxylic acid methyl ester Prepared according to the procedure mentioned in step 2 of example 1 to afford the desired product as pale yellow solid at RT instead of 0 "C. ^H NMR (300 MHz, CDCI3); 6 2.64 -2.90 (m, 4H), 3.20 - 3.5 5 (m, 2H), 3.78 (s, 3H), 4.01 (s, 3H), 4.23 (s, 3H), 6.90 (d, J = 8.4 Hz, 1H), 7.16 - 7.19 (m, 1H), 7.30 - 7,32 (m, 1H), 7.49 -7.53 (m, 2H), 8.30 (d, J= 8.2 Hz, 1H), 12.33 (s, 1H). Step 3: Preparation of 4-(1-methoxy-9-methyl-9H-carbarol-4-yl)-cyclohexanone Prepared according to the procedure mentioned in step 3 of example 1 to afford the desired product as a pale yellow solid. IR (KBr) (cm-1): 3421, 2959, 2224, 1719, 1574, 1474, 1322, 1274, 1247, 1104, 1017, 799, 754. 'H NMR (300 MHz. CDCI3): 6 2.28 - 2.37 (m, 2H), 2.64 - 2.70 (m, 2H), 3.00 - 3.15 (m, 4H), 4.01 (s, 3H), 4.24 (s, 3H), 6.90 (d, J =8.3 Hz, 1H), 7.10 (d, J =8.3 Hz, 1H), 7.31 - 7.36 (m, 1H), 7.48 - 7.57 (m, 2H), 8.39 (d, J = 8.3 Hz, 1H). Example 9 Step 1: Preparation of 3-dimethylaminomethylene-1-(6-fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-4-oxo-cyclohexanecarbonitrile A stirred solution of 4-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-cyclohexanone (example 7) (1g, 2.46 mmole) in DMF (7 ml) and DMA.DMF (588 mg, 4.93 mmole) was heated to 110° C. After 2h, the starting material was absent by TLC and the reaction mass was cooled to RT. The mixture was diluted with water (20 ml) and extracted with ethyl 36 acetate (3 X 25 ml). The combined organic layer was washed with water (3 x 75 ml), dried over anhydrous Na2S04 and concentrated at 40 °C under vacuum. The crude product was purified by column chromatography to give the title compound (900 mg, yield 77.8%). Step 2. Preparation of 6-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-5,6,7,8- tetrahydroquinazoline-6-carbonitrile To a solution of step 1 (100 mg, 0.24 mmole) and formamidine acetate (256 mg, 2.46 mmole) in DMA (3 ml) was stirred under micro wave in a micro oven for 10 minutes. The reaction mass was cooled to room temperature and aqueous sodium bicarbonate (10 ml) was added. The mixture was extracted with dichloromethane (3x5 ml). The combined organic layer was washed with water (3 x 10 ml), dried over anhydrous Na2S04 and concentrated. The residue was purified by column chromatography to afford the desired product (60 mg, yield 64.8%) as a pale yellow solid. 'H NMR(300MHZ, DMSO-de): S 2.43 - 2.62 (m, 1H), 2.90 - 3.35 (m, 3H), 3.65 (d, J= 15.6 Hz, 1H), 3.85(d, J= 16.3 Hz, 1H), 4.00 (s, 3H), 4.22 (s, 3H), 7.08-7.17 (m, 2H), 7.41 -7.48 (m, 1H), 7.72 - 7.76 (m, 1H), 7.95 (dd, J = 11.1 Hz and 2.0 Hz, 1H), 8.76 (s, 1H), 9.03 (s, 1H). IR (KBr) (cm "^); 3435, 2990, 2227, 1779, 1602, 1578, 1512, 1486, 1458, 1392, 1313, 1274, 1242,1200,1026,783. Step 1: Preparation of 3-Dimethylaminomethylene-1-(6-fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-4-oxo-cyclohexanecarbonitrile The title compound was prepared according to a similar procedure mentioned in step 1 of example 9 Step 2: Preparation of 2-Amino-6-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)- 5,6,7,8-tetrahydroquinazoline-6-carbonitrile To a stirred solution of step 1 (90 mg, 0.22 mmole) in ethanol (3 ml) was added guanidine.HCI (23 mg, 0.24 mmole) followed by sodium ethoxide (18.1 mg, 0.26) at RT. After refluxing for 2h (the starting material was absent by TLC) the reaction mixture was concentrated at 40''C under vacuum, diluted with water (10 ml) and extracted with dichloromethane (3x5 ml). The combined organic layer was washed with water (3X10 ml), dried over anhydrous Na2S04 and concentrated. The crude product was purified by column chromatography to afford the desired product (50 mg, yield 56 %) as a pale yellow solid. 'H NMR (300 MHz, DMSO- dg); 5 2.43 - 2.50 (m, 1H), 2.80 - 3.10 (m, 3H). 3.22 - 3.37 (m, 1H), 3.57-3.62 (m, 1H), 3.99 (s, 3H), 4.21 (s, 3H), 6.51 (s, 2H), 7.08 - 7.18 (m, 2H), 7.41 -7.47 (m, 1H), 7.71 - 7.76 (m, 1H), 7.90 - 7.95 (dd, J= 11.2 Hz and 2.3 Hz, 1H), 8.18(s, 1H). IR (KBr) (cm "^): 3420, 3179, 2933, 2231, 1657, 1599, 1579, 1510, 1484, 1462, 1391, 1315, 1270, 1241, 1199, 1027,793. Step 1: Preparation of 3-Dimethylaminomethylene-1-(6-fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-4-oxo-cyclohexanecarbonitrile The title compound was prepared according to a similar procedure mentioned in step 1 of example 9 Step 2: Preparation of 5-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-4,5,6,7- tetrahydro-2H-indazole-S-carbonitrile A solution of step 1 (90 mg, 0.22 mmole) and hydrazine hydrate (13 mg, 0.26 mmole) in ethanol (3 ml) was refluxed for 6h. Starting material was absent by TLC and the reaction mass was concentrated at 40''C under vacuum. The mixture was diluted with water (10 ml) and extracted with dichloromethane (3x5 ml). The combined organic layer was washed with water (3x10 ml), dried over anhydrous Na2S04 and concentrated. The residue was purified by column chromatography to afford the desired product (65 mg, yield 78.3 %) as a pale yellow solid. Step 1: Preparation of 3-Dimethylaminomethylene-1-(6-fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-4-oxo-cyclohexanecarbonltrile The title compound was prepared according to a similar procedure mentioned in step 1 of example 9 Step 2; Preparation of 5-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-4,5,6,7- tetrahydro-benzo[c]isoxazole-S-carbonitrile To a stirred solution of hydroxylamine.HCI (21 mg, 0.30 mmole) in ethanol (3 ml) and sodium ethoxide (20 mg, 0.30 mmole) was added step 1 (100 mg, 0.25 mmole) at RT. After stirring for 1 h (the starting material was absent by TLC) the reaction mass was concentrated under vacuum, diluted with water (10 ml) and extracted with ethyl acetate (3X5 ml). The combined organic layer was washed with water (3 x 10 ml), dried over anhydrous Na2S04 and concentrated. The crude product was purified by column chromatography to afford the desired product (60 mg, yield 64.5 %) as a pale yellow solid. ^H NMR (300 MHz, DMSO- de): 5 2.2 - 3.50 (m, 6H), 3.98 (s, 3H), 4.19 (s, 3H), 7.04 - 7.13 (m, 2H), 7.41 - 7.47 (m, 1H), 7.70 - 7.75 (m, 2H), 7.93 (dd, J = 11.0 Hz and 2.08 Hz, 1H). IR(KBr)(cm"^):3436, 2938, 2231, 1627, 1579, 1513, 1484, 1463, 1315, 1274, 1190,907. Example 13 Step 1: Preparation of 3-Dimethylaminomethylene-1-(6-fluoro-1-mGthoxy-9-methyl-9H-carbazol-4'yl)-4-oxO'Cyclohexanecarbonitrile The title compound was prepared according to a similar procedure mentioned in step 1 of example 9 Step 2: Preparation of 6-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-2-methyl- 5,6,7,8-tetrahydroquinazorme-6-carbonitrile To a stirred solution of step 1 (100 mg, 0.25 mmoie) in ethanol (3 ml) was added acetamidine.HCI (47 mg, 0.50 mmoie) followed by sodium methoxide (27 mg, 0.50 mmole) at RT. After refluxing for 2h (the starting material was absent by TLC) the reaction mass was concentrated at 40^0 under vacuum, diluted with water (10 ml) and extracted with dichloromethane (3x5 ml). The combined organic layer was washed with water (3x10 ml), dried over anhydrous Na2S04 and concentrated. The residue was purified by column chromatography to afford the desired product (50 mg, yield 50 %) as a pale yellow solid. ^H NMR (300 MHz, DMSO- de): 5 2.50 - 2.60 (m, 3H), 2.80 - 3.30 (m, 3H), 3.58 (d, J = 16.5 Hz, 1H), 3.80 (d, J = 16.5 Hz, 1H), 3.99 (s, 3H), 4.22 (s, 3H), 7.08 - 7.17 (m, 2H), 7.42 - 7.48 (m, 1H), 7.72-7.77 (m, 1H), 7.95 (d, J= 11.1 Hz, 1H), 8.64 (s, 1H). IR (KBr) (cm "^): 3434, 2942, 2226, 1735, 1580, 1556, 1484, 1434, 1315, 1273, 1199, 1187, 920, 792. step 1: Preparation of 3-Dimethylaminomethylene-1-(1-methoxy-9-methyl-9H-carbazol-4-yl)-4-oxo-cyclohexanecarbonitrile A solution of 4-(1-nnethoxy-9-methyl-9H-carbazol-4-yl)-heptanedioic acid dimethyl ester (example 8) (530 mg, 1.59 mmole) and DMA.DMF (379.9 mg, 3,19 mmole) in benzene (10 ml) was stirred at refluxed. After 2hours, the reaction mass was concentrated at 40° C under vacuum and the crude product was purified by column chromatography to yield the title compound (270 mg, yield 43.6%) and the starting material (290 mg, 54.7%) Step 2: Preparation of 6-(1-methoxy-9-methyl-9H-carbazol-4-yl)-5,6,7,8- tetrahydroquinazoline-6-carbonitrile A mixture of step 1 (104 mg, 0.27 mmole) in DMA (3 ml) and formamidine acetate (419,2 mg, 4.03 mmole) was exposed to microwave for 10 min in a household micro oven. The starting material was absent by TLC and the reaction mass was cooled to RT, To this was added aqueous sodium bicarbonate (10 ml) and the mixture was extracted with dichloromethane (3 x 5 ml). The combined organic layer was washed with water (3 x 10 ml), dried over anhydrous Na2S04 and concentrated. The crude product was purified by column chromatography to yield the desired product (79 mg, yield 79.8%) as an off-yellow colored solid. ^H NMR (300 MHz, CDCI3): 6 2.43 - 3.70 (m, 6H), 4.02 (s, 3H), 4,25 (s, 3H), 6,88 (d, J = 8.0 Hz, 1H), 7.06 (d, J = 8.6 Hz, 1H), 7.33 (t, J = 6.7, 1H), 7,50 - 7.59 (m, 2H), 8.34 (d, J = 8.3 Hz, 1H), 8.69(s, 1H), 9.15 (s, 1H), IR (KBr) (cm "^): 3431, 2927, 2857, 2225, 1731, 1616, 1575, 1553, 1509, 1475, 1395, 1321, 1279, 1246, 749,731. Step 1: Preparation of 3-Dimethylaminomethylene-1-(1-methoxy-9-methyl-9H-carbazol-4-yl)-4-oxo-cyclohexanecarbonitrile The title compound was prepared according to a similar procedure mentioned in step 1 of example 14 Step 2: Preparation of 2-Amino-6-(1-methoxy-9-methyl-9H-carbazol-4-yl)-5,6,7,8- tetrahydroquinazoline-6-carbonitrile To a stirred solution of step 1 (110 mg, 0.28 mmole) in ethanol (3 ml) was added guanidine.HCI (29.8 mg, 0.31 mmole) followed by sodium ethoxide (23.2 mg, 0.34 mmole) at RT, After refluxing for 2h (the starting material was absent by TLC) the reaction mass was concentrated under vacuum, diluted with water (10 ml) and extracted with ethyl acetate (3 x 5 ml). The combined organic layer was washed with water (3x10 ml), dried over anhydrous Na2S04 and concentrated. The residue was purified by column chromatography to afford the desired product (95 mg, yield 87.3 %) as a pale yellow solid. ^H NMR (300 MHz, CDCI3): 6 2.43 - 3,70 (m, 6H), 4.00 (s, 3H), 4.21 (s, 3H), 6.50 (s, 2H), 7.09 (d, J =8.4 Hz, 1H), 7.17 (d, J = 8.3 Hz, IN), 7.31 (t, J = 7,6 Hz, IN), 7.54 (t, J = 7,7 Hz, 1H), 7,69 (d, J= 8.3 Hz, 1H), 8.17 (s, 1H), 8.26 (d,J=B.2 Hz, 1H), IR (KBr) (cm "^): 3395, 3330, 3175, 2934, 2225, 1662, 1599, 1574, 1474, 1323, 1295, 1272, 1108,793,754, Step 1: Preparation of 3-dimethylaminomethylene-1-(1-methoxy-9-methyl-9Ay-carbazol-4-yl)-4-oxo-cyclohexanecarbonitrile The title compound was prepared according to a similar procedure mentioned in step 1 of example 14 Step 2: Preparation of 5-(1-methoxy-9-methyl-9H-carbazol-4-yl)-4,5,6,7-tetrahydro-2H- indazole-5-carbonitrile A solution of step 1 (100 mg, 0.26 mmole) and hydrazine hydrate (15.5 mg, 0.31 mmole) in ethanol (4 ml) was refluxed for 2h, Starting material was absent by TLC and the reaction mass was concentrated at 40''C under vacuum. Water (10 ml) was added and the mixture was extracted with dichloromethane (3x5 ml). The combined organic layer was washed with water (3X10 ml), dried over anhydrous Na2S04 and concentrated. The crude product was purified by column chromatography to afford the desired product (63 mg, yield 68.5 %) as an off-yellow solid, ^H NMR (300 MHz, DMSO- de): 6 2.39 - 3,58 (m, 6H), 4,00 (s, 3H), 4,21 (s, 3H), 7,07 (d, J = 8,4 Hz, 1H), 7,22 - 7.30 (m,2H), 7.50 - 7.55 (m, 2H), 7.67 (d, J = 8A Hz, 1H), 8.23 (d, J = 7.0 Hz, 1H), 12.58 (s, 1H). IR (KBr) (cm "^): 3393, 2932, 2854, 2230, 1616, 1574, 1508, 1475, 1395, 1323, 1275, 1102, 1020,957,752,735, step 1: Preparation of 3-Dimethylaminomethylene-1-(1-methoxy-9-methyl-9H-carba2ol-4-yl)-4-oxo-cyclohexanecarbonitrile The title compound was prepared according to a similar procedure mentioned in step 1 of example 14 Step 2: Preparation of 5-(1-methoxy-9-methyl-9H-carbazol-4-yl)-4,5,6,7-tetrahydro- benzo[c]isoxazole-5-carbonitrile To a stirred solution of hydroxylamine.HCI (20mg, 0.28 mmole) and sodium ethoxide (19.3 mg, 0.28 mmole) in ethanol (5ml) was added compound of step 1 (100 mg, 0.25 mmole) at RT. After stirring for 16 h (the starting material was absent by TLC) the reaction mass was concentrated under vacuum, diluted with water (10 ml) and extracted with ethyl acetate (3 x 5 ml). The combined organic layer was washed with water (3 x 10 ml), dried over anhydrous NaaSO^ and concentrated under vacuum. The residue was purified by column chromatography to afford the desired product (60 mg, yield 65 %). ^H NMR (300 MHz, CDCI3): 5 2.00 - 3.68 (m, 6H), 3.99 (s, 3H), 4.22 (s, 3H), 6.86 (d. J = 8.2 Hz, 1H), 6.99 (d, J = 8.1 Hz, 1H), 7.34 (t, J = 7.08, 1H), 7.41 - 7.56 (m, 3H), 8.35 (d, J = 8 Hz, 1H). IR (KBr) (cm "^): 3308, 2956, 2923, 2853, 2225, 1713, 1573, 1509, 1465, 1398, 1322. 1276, 1188,1021,754. Step 1: Preparation of 4-cyano-4-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-heptanedioic acid dimethyl ester The title compound was prepared using the intermediate 4, according to a similar procedure mentioned in step 1 of example 1. In this example we used triton B as a base instead of 1,1,3,3-tetramethyl guanidine under reflux. ^H NMR (300 MHz, DMSO-de): 5 2.4 - 2.8 (m, 8H), 3.50 (s, 6H), 3.99 (s, 3H), 4.20 (s, 3H), 7.09 - 7.17 (m,2H), 7.40-7.46 (m, 1H), 7.7-7.74 (m, 1H), 8.05 (d, J= 10.7 Hz, 1H). Step 2: Preparation of 5-cyano-5-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-2-oxo cyclohexanecarboxylic acid methyl ester To a stirred solution compound of step 1 (175 mg, 0.40 mmole) in dimethoxyethane (5 ml), was added 60% NaH in paraffin oil (20 mg, 0.50 mmole) and stirred for 1 hour at room temperature. Reaction was monitored by TLC and the starting material was absent. The reaction mass was quenched with water (10 ml) and extracted with ethyl acetate (2 x 20 ml). The combined organic layer was dried the organic layer over anhydrous NaaSO^ and concentrated to the desired product (125 mg, yield 77.2%) as pale yellow solid. M NMR (300 MHz, DMSO-de): 5 2.64 - 2.90 (m, 4H), 3.20 - 3.5 5 (m, 2H), 3.76 (s, 3H), 3,99 (s, 3H), 4.21 (s, 3H), 7.1 - 7.20 (m, 2H), 7.40 - 7.50 (m, 1H), 7.7 - 7.79 (m, 1H), 7.89 (d, J = 9.2 Hz, 1H), 12.14 (s, 1H) MS: 409.3 (M*+1) Step 3: Preparation of 6-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-4-oxo-3,4,5,6,7,8-hexahyclroquinazoline-6-carbonitrile A mixture of intermediate 1 (100 mg, 0.25 mmole) and formamidine acetate (255 mg, 2.5 mmole) in DMA (3 ml) was exposed to micro wave for 10 min in a iiousehold micro oven. The reaction mass was cooled to room temperature, diluted with water (10 ml) and extracted with dichloromethane (3x5 ml). The combined organic layer was washed with water (3x10 ml), dried over anhydrous Na2S04 and concentrated under vacuum. The crude product was purified by column chromatography to yield desired product (65 mg, yield 66%) as an off-yellow colored solid. ^H NMR (300 MHz, DMSO- de): 5 2.70 - 3.80 (m, 6H), 3.99 (s, 3H), 4.21 (s, 3H), 7.02 -- 7.12 (m,2H), 7.44(t, J=7.9H2, 1H), 7.71 - 7.76 (m, 1H), 7,93 (d, J= 11.4 Hz, 1H), 8.12(s, 1H), 12.55 (s, 1H). IR(KBr)(cm"'):3435. 2915, 2230, 1644, 1579, 1484, 1315, 1271, 1191, 1086,795. Preparation of 2-Amino-6-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-4-oxo-3,4,5,6,7,8-hexahydroquinazoline-6-carbonitrile To a stirred solution of step 2 of example 18 (90 mg, 0.22 mmole) in ethanol (3 ml) was added guanidine.HCI (26 mg, 0.27 mmole) followed by sodium ethoxide (20 mg, 0.29 mmole) at room temperature. After refluxing for 4hours (the starting material was absent by TLC) the reaction mass was concentrated under vacuum, diluted with water (10 ml) and extracted with ethyl acetate (3x5 ml). The combined organic layer was washed with water (3x10 ml), dried over anhydrous Na2S04 and concentrated. The residue was purified by column chromatography to yield the desired product (65 mg, yield 52 %) 'H NMR (300 MHz, DMSO- dg): 5 2,30 - 3.70 (m, 6H), 3.99 (s, 3H), 4.21 (S, 3H), 6.44 (s, 2H), 7.09-7.16 (m, 2H), 7.39 - 7.46 (m, 1H), 7.70 - 7.75 (m, IN), 7.90 (d, J = 8.9 Hz, 1H), 10.89 (s, 1H). IR (KBr) (cm "^): 3445, 2927, 2229, 1652, 1484, 1390, 1270, 1192, 1038, 777. Example 20 Preparation of 5-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-3.oxo-3,3a,4,5,6,7-hexahydro-2H-indazole-5-carbonitrile A solution of compound of step 2 of example 18 (100 mg, 0,25 mmole) and hydrazine hydrate (18 mg, 0.36 mmole) in ethanol (3 ml) was refluxed for 6h (the starting material was absent by TLC). The reaction mass was concentrated under vacuum, diluted with water (10 ml) and extracted with dichloromethane (3x5 ml). The combined organic layer was washed with water (3x10 ml), dried and concentrated under vacuum. The residue was purified by column chromatography to afford the desired product (70 mg, yield 73.2 %). ^H NMR(300MHz, DMSO-de): 6 2.40 - 3.50 (m, 6H), 3.99 (s, 3H), 4.21 (s, 3H), 7.11 (d, J = 8.4 Hz, 1H), 7.23 (d, J = 6.5Hz, 1H), 7.42 (t, J = 8.8 Hz, 1H), 7.70 - 7.74 (m, 1H), 7.87 (m, 1H), 11.32 (s, 1H) IR (KBr) (cm "^): 3436,2934,2230, 1625, 1580, 1484, 1384, 1315, 1273, 1241, 1191,934. Example 21 Preparation of 6-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-2-methyl-4-oxo-3,4,5,6,7,8-hexahydroquinazoline-6-carbonltrlle To a stirred solution of compound of step 2 of example 18 (100 mg, 0.25 mmole) in methanol (3 ml) was added acetamidine.HCI (46 mg, 0.50 mmole) followed by sodium methoxide (27 mg, 0.50 mmole) at room temperature and the mixture was refluxed for 2h. After completion of the reaction (indicated by TLC) the reaction mass was concentrated at 40°C under vacuum, diluted with water (10 ml) and extracted with dichloromethane (3x5 ml). The combined organic layer was washed with water (3x10 ml), dried over anhydrous Na2S04 and concentrated. The residue was purified by column chromatography to afford the desired product (70 mg, yield 68.6 %) as a pale yellow solid. ^H NMR (300 MHz, DMSO- ds): 6 2.25 (s, 3H), 2,44 - 2.94 (m, 4H), 3.56 - 3.62 (m, 2H), 3.99 (s, 3H), 4.21 (s, 3H), 7.09 - 7.15 (m, 2H), 7.40 - 7.46 (m, 1H), 7.70 - 7.75 (m, 1H), 7.90 -7.94 (m, IN). IR (KBr) (cm "^): 3423, 2934, 2841, 2233, 1651, 1611, 1580, 1513, 1483, 1315, 1240, 1192, 1028,925, 864. Step 1: Preparation of 4-{1-methoxy-9-methyl-9H-carbazol-4-yl)-heptanedioic acid dimethyl ester The title compound was prepared using the intermediate 5, according to a similar procedure mentioned in step 1 of example 1. In this example we used triton B as a base instead of 1,1,3,3-tetramethyl guanidine under reflux. 'H NMR (300 MHz, CD3OD): 5 2.2 - 2.8 (m, 8H), 4.02 (s, 6H), 4.22 (s, 3H), 4.57 (s, 3H), 7.03 (d, J = 8,3 Hz, 1H), 7.24 - 7.34 (m, 2H), 7.47 - 7.58 (m, 2H), 8.33 (d, J = 7.7 Hz, 1H) Step 2: Preparation of 5-(1-methoxy-9-methyl-9H-carbazol-4-yl)-2-oxocyclohGxane carboxylic acid methyl ester To a stirred solution of compound of step 1 (190 mg, 0.45 mmoie) in dimethoxy ethane (3 ml), was added 60% NaH in paraffin oil (20 mg, 0.5 mmole) and the mixture was stirred for 2 h at RT. The reaction was monitored by TLC. After disappearance of starting material the reaction mass was quenched with water (10 ml) and extracted with ethyl acetate (2x10 ml). The combined organic layer was dried over anhydrous Na2S04, concentrated and dried to afford the desired product as a pale yellow solid (100 mg, yield 57%). ^H NMR (300 MHz, CDCI3): 5 2.64 - 2.90 (m, 4H), 3.20 - 3,5 5 (m, 2H), 3.78 (s, 3H), 4,01 (s, 3H), 4.23 (s, 3H), 6.90 (d, J = 8.4 Hz, 1H), 7.16 - 7,19 (m, 1H), 7.30 - 7.32 (m, 1H), 7.49 - 7.53 (m, 2H), 8.30 (d, J= 8.2 Hz, 1H), 12.33 (s, 1H) Step 3: Preparation of 2-Amino-6-(1-methoxy-9-methyl-9H-carba2ol-4-yl)-4-oxo- 3,4,5,6,7,8-hexahydroquinazoline-6-carbonltrile To a stirred solution of step 2 (200 mg, 0.51 mmole) in ethanol (10 ml) was added guanidine.HCI (59 mg, 0.61 mmole) followed by sodium ethoxide (45 mg, 0.66 mmole) at RT, After refluxing for 8h (the starting material was absent by TLC) the reaction mass was concentrated at 40''C under vacuum, diluted with water (10 ml) and extracted with ethyl acetate (3x5 ml). The combined organic layer was dried over anhydrous Na2S04 and concentrated under vacuum. The residue was purified by column chromatography to afford the desired product (110 mg, yield 53.9 %). 'H NMR (300 MHz, DMSO- dg): 8 2.37 - 3.55 (m, 6H), 3,99 (s, 3H), 4.20 (s, 3H), 6.43 (s, 2H), 7.07-7.16 (m, 2H), 7,27 (t, J= 7.6 Hz, 1H), 7,52 (t, J= 7.6 Hz, 1H), 7.68 (d, J= 8.2 Hz, 1H), 8.23 (d, J= 8.3 Hz, 1H), 10.88 (s, 1H). IR (KBr) (cm ■^): 3430, 2933, 2228, 1637, 1509, 1475, 1385, 1324, 1272, 1111, 1029,752. Preparation of 5-(1-methoxy-9-methyl-9H-carbazol-4-yl)-3-oxo-3,3a,4,5,6,7-hoxahydro-2H-indazole-5-carbonitrile A solution of compound of step 2 of example 22 (120 mg, 0.31 mmoie) and hydrazine hydrate (23 mg, 0.46 mmole) in ethanol (10 ml) was refluxed for 2h. After completion of the reaction (indicated by TLC) the reaction mass was concentrated, diluted with water (10 ml) and extracted with ethyl acetate (3x5 ml). The combined organic layer was washed with water (3x10 ml), dried over anhydrous Na2S04 and concentrated. The residue was purified by column chromatography to afford the desired product (75 mg, yield 65.8 %) as a pale yellow solid. ^H NMR (300 MHz. DMSO- dg): 5 2.30 - 3.60 (m, 6H), 4.00 (s, 3H), 4.20 (s, 3H), 7.09 (d, J = 8,4 Hz, 1H), 7.23 - 7.30 (m, 2H), 7.52 (t, J = 7.62 Hz, 1H), 7.67 (d, J = 8.2 Hz, 1H), 8.20 (d, J = 8.4 Hz, 1H), 11.35 (s, 1H) IR (KBr) (cm ■^): 3435,2933,2229, 1627, 1577, 1485, 1385, 1314, 1272, 1189,935. Step 1: Preparation of (1-Methoxy-9-methyl-6-nitro-9/y-carbazol-4-yl)-methanol: To a suspension of 1-methoxy-9-methyl-6-nitro-9H-carbazole-4-carboxylic acid (this compound is prepared as per the procedure mentioned in US20070105855) (13 g, 43.33 mmol) in dry tetrahydrofuran (THF) (1340 ml) was added borane dimethylsulfide complex (21.4 ml, 281.66 mmol) slowly at 0 °C for one hour under a nitrogen atmosphere and then the mixture was stirred at room temperature for 18 hours. The reaction was monitored by TLC (50 % EtOAc/hexane). The reaction mass was concentrated under vacuum at 30 °C and to the resulting solid was added cold potassium carbonate (K2CO3) solution (60 g in 200 ml water) at 0-5 °C in 1 hour. The precipitated solid was filtered after 30 minutes, washed with water and dried under vacuum at 50''C for 8 hours to afford the titled compound (10.65 g, 87 %). mp: 211-213.6-0. IR (KBR) cm"1 3369, 2838, 1620, 1579, 1513, 1325, 1307, 1263, 1075. ^H NMR (300 MHz, DMSO-de) 5 3.9 (s, 3 H), 4.2 (s, 3 H), 5.0 (d, 2 H, J = 6.0 Hz, D2O exchangable), 5.3 (t, 1 H, J = 6.0 Hz), 7.1 (d, 1 H, J = 0.03 Hz), 7,2 (d, 1 H, J = 9.0 Hz), 7.7 (d, 1 H, J = 9.0 Hz), 8.3 (dd, 1 Hz, J = 3.0 Hz, 9.0 Hz), 9.0 (d, 1 H, J = 3.0 Hz). Step 2: Preparation of 4-Chloromethyl-1-methoxy-9-methyl-6-nitro-9H-carbazolB: To a suspension of (1-methoxy-9-methyl-6-nitro-9H-carbazol-4-yl)-methanol (7.2 g, 26.2 mmol) in EtOAc (1050 ml) was added SOCIj (39.0 ml, 524.4 mmol) slowly at room temperature for 30 minutes and then the mixture was stirred at the same temperature for 2 hours. The reaction was monitored by TLC (50 % EtOAc/hexane). After completion of the reaction EtOAc was removed under vacuum and to the residue was treated with ethyl acetate (20 ml) which was removed again completely. Small amount of product was isolated by triturating it with hexane for characterization purpose and the remaining amount was directly taken for the next step. DSC: ''H NMR (300 MHz, DMSO-de) 6 4.0 (s, 3 H), 4.2 (s, 3 H), 5.3 (s, 2 H), 7.1 (d, 1 H, J = 9.0 Hz), 7.3 (d, 1 H, J = 9.0 Hz), 7.8 (d, 1 H, J = 9.0 Hz), 8.3 (dd, 1 Hz, J = 3.0 Hz, 9.0 Hz), 9.0 (d, 1 H, J = 3.0 Hz). Step 3: Preparation of (1-Methoxy-9-methyl-6-nitro-9H-carbazol-4-yl)-acetonitrile: To a solution of 4-chloromethyl-1-methoxy-9-methyl-6-nitro-9H-carbazole in DMF (240 ml) was added sodium cyanide (NaCN) (2,4 g, 49.0 mmol) and the mixture was stirred at room temperature for 18 hours. The reaction mass was then diluted with water (2.0 liter) and the precipitated solid was filtered. The solid was washed with water and dried under vacuum at 55 °C for 8 hours to give the cyano compound (6.1 g, 84.7 %). mp: 266.5-267.5 "C. IR (KBR) cm"1 3436.12, 2256.74, 1504.56, 1335.25, 1314.86, 1268.94, 1075.46, 796.01. DSC: 285.48''C. ^H NMR (300 MHz, DMSO-de) 6 4.0 (s, 3 H), 4.2 (s, 3 H), 4.6 (s, 2 H), 7.1 (d, 1 H, J = 9.0 Hz), 7.2 (d, 1 H, J = 9.0 Hz), 7.8 (d, 1 H, J = 9.0 Hz), 8.3 (d, 1 Hz, J = 9.0 Hz, 9.0 Hz), 9.0 (s, 1 H). Step 4: Preparation of 4-Cyano-4-(1-methoxy-9-methyl-6-nitro-9H-carbazol-4-yl)-heptanedioic acid dimethyl ester: To a suspension of (1-methoxy-9-methyl-6-nitro-9/-/-carbazol-4-yl)-acetonitrile (4.0 g, 13.55 mmol) in DMSO (120 ml) was added methyl acrylate (23.3 ml, 271 mmol) followed by 1,8-Diazabicycioundec-7-ene (DBU) (4.5 g, 29.83 mmol) at room temperature and the mixture was stirred for 4 hours at the same temperature. The reaction mass was cooled to 15 °C, diluted with water (400 ml) and extracted with ethyl acetate (8 x 200 ml). The combined ethyl acetate layer was collected, washed with water followed by brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The crude product was purified by column chromatography using silica gel (100-200) and 10 % ethyl acetate/ hexane to afford the title compound (2.2 g, 35 %). mp: 166-168 "C, IR (KBR) crnl 3453.59, 2953.70, 2930.91, 2228.51, 1745.21, 1573.51, 1509.27, 1327.24, 1313.55, 808.15. ^H NMR (300 MHz, CDCI3) 5 2.3-2.7 (m, 6 H), 2.8-3.1 (m, 2 H), 3.6 (s, 6 H), 4.0 (s, 3 H), 4.2 (s, 3 H), 7.0 (d, 1 H, J = 9.0 Hz), 7.36 (m, 1 H), 7.5 (d, 1 H, J = 9.0 Hz), 8.4 (dd, 1 Hz, J = 3.0 Hz, 9.0 Hz), 9.3 (br s, 1 H). Step 5: Preparation of 5-Cyano-5-(1-metlioxy-9-methyl-6-nitro-9W-carbazol-4-yl)-2-oxo-cyclohexanecarboxylic acid methyl ester: To a solution of 4-cyano-4-(1-methoxy-9-methyl-6-nitro-9H-carbazol-4-yl)-heptanedioic acid dimethyl ester (2.0 g, 4.2 mmol) in dry DMF (40 ml) was added sodium hydride (NaH) (287 mg, 5.99 mmol, 50 %) portion wise at 0 °C for 5 minutes and the mixture was stirred at the same temperature for 1 hour. To this mixture was added saturated ammonium chloride. The mixture was then diluted with water, extracted with 20% MeOH/CHCb (6 x 200 ml) and concentrated under vacuum. The residue was treated with water (200 ml) and the precipitated solid was filtered, washed with water and dried under vacuum to afford the title compound (1.4 g, 75.2 %). mp: 215-216.5 "C. IR (KBR) cm"1 3436,04, 2954.18, 2924.16, 2228.63, 1664.32, 1619.61, 1572.51, 1514.36, 1313.66, 1220.6, 1077.19. ^H NMR (300 MHz, CDCI3) 5 2.41-2.53 (m, 2 H), 2.72-2.77 (m, 1 H), 2.88-3,0 (m, 3 H), 3.5 (d, 1 H, J = 18.0 Hz), 3.8 (s, 3 H), 4.0 (s, 3 H), 4,2 (s, 3 H), 7.0 (d, 1 H, J = 9 Hz), 7.5 (d, 1 H, J = 9 Hz), 8.4 (dd, 1 H, J = 3.0 Hz, & 9.0 Hz), 9.3 (d, 1 H, J = 3 Hz), 12.3 (s, 1 H). Step 6: Preparation of 1-(1-Methoxy-9-methyl-6-nitro-9H-carbazol-4-yl)-4-oxo-cyclohexanecarbonitrile: To a solution of 5-cyano-5-(1-methoxy-9-methyl-6-nitro-9H-carbazol-4-yl)-2-oxo-cyclohexanecarboxylic acid methyl ester (1.0 g, 2.29 mmol) in DMSO (35 ml) was added LiBr (257 mg, 2.98 mmol) at room temperature and the mixture was stirred at 130 °C for 5 hours. The reaction was monitored by TLC (50 % EtOAc/hexane), After cooling to RT the reaction mixture was diluted with water (280 ml) and extracted with 20% MeOH/CHCIa (6 x 100 ml). The organic layers were collected, combined and concentrated under vacuum. The concentrated mass containing dimethyl sulphoxide (DMSO) was diluted with 100ml of water and the precipitated solid was filtered, washed with water and dried under vacuum at 50 °C which was purified by column chromatography to afford the title compound (600 mg, 69.28 %). mp: 227-229 "C, IR (KBR) cm"1 3430.69, 2960.55, 2921.48, 2227.56, 1725.73, 1618.16, 1569.43, 1516.11, 1310.38, 1270,94, 1072.27. ^H NMR (300 MHz, CDCI3) 6 2,25-2.34 (m, 2 H), 2,70-2,76 (m, 2 H), 3,09-3,25 (m, 4 H), 4.0 (s, 3H), 4.29 (s, 3 H), 7,0 (d, 1 H, J = 9 Hz), 7.2 (d, 1 H, J = 9 Hz), 7.5 (d, 1 H, J = 9 Hz), 8,4 (dd, 1 H, J = 3,0 Hz, & 9,0 Hz), 9.45 (d, 1 H, J = 3 Hz). Preparation of 6-(1 -Methoxy-9-methyl-6-nitro-9H-carbazol-4-yl)-5,6,7,8-tetrahydro-quinazoline-6-carbonitrile: To a solution of compound of example 24 (100 mg, 0.265 mmol) in DMF (5 ml) was added DMF.DMA (70.6 pi, 0.53 mmol) at room temperature and the mixture was stirred at 110 °C for 2 hours. The reaction was monitored by TLC (5 % MeOH/CHCIa), The mixture was diluted with cold water (30 ml) and then extracted with ethyl acetate (5 x 20 ml). The combine organic layer was washed with water (3 x 20 ml), dried over anhydrous Na2S04 and concentrated under vacuum to give the crude enamine intermediate which was treated with formamidine acetate (273 mg, 2.65 mmol) in A/./V-dimethyl acetamide (2 ml) under MW for 10 minutes. After completion of the reaction, [monitored by TLC (5 % MeOH/CHCy], the reaction mass was diluted with cold water and extracted with ethyl acetate (4 x 20 ml). The combined organic layer was washed with water, brine, then dried over anhydrous Na2S04 and concentrated under vacuum. The crude solid was purified by column chromatography (100-200 silica gel) using CHCI3 to afford the title compound (80 mg, 72 %). ^H NMR (300 MHz, CDCI3) 5 2.63-2.68 (m, 1 H), 3.01-3.08 (m, 2 H), 3.46 (m, 1 H), 3.6 (d, 1 H, J = 15 Hz), 3.8 ((d, 1 H, J = 15 Hz), 4.0 (s, 3 H), 4.3 (s, 3 H), 6.9 (d, 1 H, J = 9.0 Hz), 7.1 (d, 1 H, J = 9.0 Hz), 7.5 (d, 1 H, J = 9.0 Hz), 8.4 (d, 1 H, J = 9.0 Hz), 8.6 (s, 1 H), 9.1 (s, 1 H), 9.4 (s, 1 H). Preparation of A/-[5-(6-Cyano-5,6,7,8-tetrahydro-quinazolin-6-yl)-8-methoxy-9-methyl-9H-carbazol-3-yl]-methanesulfonamide: To a suspension of compound of example 25 (150 mg, 0.353 mmol) in EtOH/water (15 ml, 2:1) was added iron powder (150 mg, 2.68 mmol) and ammonium chloride (NH4CI) (150 mg, 2.80 mmol) and the mixture was refluxed for 3 hours. After completion of the reaction, [monitored by TLC (5 % MeOH/CHCIa)], the mixture was cooled to room temperature and filtered. The residue was washed with chloroform. The filtrate was collected, diluted with water and extracted with chloroform. The combined organic layer was which washed with brine and dried over anhydrous Na2S04 After concentrating under vacuum, the crude amine was dissolved in methylene dichloride - tetrahydrofuran (MDC-THF) (8 ml, 1:1) and cooled to 0 °C. To this was added mesyl chloride (MsCI) (76.4 pi, 0.939 mmol) in tetrahydrofuran (THF) (1 ml) and pyridine (247.5 pi, 3.13 mmol) and the mixture was stirred at the same temperature for one hour, The reaction mass was diluted with water (20 ml) and extracted with chloroform (3 x 30 ml). The combined organic layer was washed with bhne, dried over anhydrous sodium sulphate (Na2S04) and concentrated under vacuum to give the crude product which was purified by column chromatography (100-200 silica gel) using 0.2 % MeOH/CHCIa to afford the title compound as yellow solid (40 mg, 28 %). IR (KBr) cm"'' 3430.82, 3247.82, 2933.50, 2226.50, 1660.00, 1577.06, 1485.54, 1463.24, 1401.48, 1325.63, 1278.85, 1152.54, 973.02. HPLC Purity: 98.42 %. ^H NIVIR (300 MHz, CDCI3) 5 2.57-2.63 (m, 1 H), 2.9 (d, 1 H, J = 21 Hz), 3.0 (s, 3 H), 3.08-3.10 (m, 1 H), 3.43- 3.53 (m, 2 H), 3.9 (d, 1 H, J = 18 Hz), 4.0 (s, 3 H), 4.2 (s, 3 H), 6.5 (s, 1 H), 6.9 (d, 1 H, J = 9.0 Hz), 7.0 (d, 1 H, J = 9.0 Hz), 7.4 (dd, 1 H, J = 3.0 Hz, 9.0 Hz), 7.5 (d, 1 H, J = 9.0 Hz), 8.3 (s, 1 H), 8.6 (brs, 1 H), 9.0(brs, 1 H). Preparation of A/-[5-(1 -Cyano-4-oxo-cyclohexyl)-8-methoxy-9-methyl-9H-carbazol-3-yl]-methanesulfonamide: To a suspension of 1-(1-methoxy-9-methyl-6-nitro-9W-carbazol-4-yl)-4-oxo-cyclohexanecarbonitrile (100 mg, 0-265 mmol) in EtOH-THF-H20 (20 ml, 2:1:0.5) was added iron powder (100 mg, 1.79 mmol) and NH4CI (100 mg, 1.869 mmol) and the mixture was refluxed for 3 hours. After completion of the reaction, [monitored by TLC (5 % MeOH/CHCIa)], the reaction mass was cooled to room temperature and then filtered through celite bed. The bed was washed with chloroform. The filtrate was collected, diluted with water and extracted with chloroform. The combined organic layer was washed with brine, dried over anhydrous Na2S04 and concentrated under vacuum. The crude amine was dissolved in tetrahydrofuran (THF) (5 ml) and cooled to 0 "C. To this was added mesyl chloride (MsCI) (76.4 pi, 0.939 mmol) dissolved in tetrahydrofuran (THF) (1 ml) and pyridine (247.5 pi, 3.13 mmol) and the mixture was stirred at the same temperature for 2 hours. The reaction mass was diluted with water (20 ml) and extracted with ethyl acetate (3 x 40 ml). The combined organic layer was washed with brine, dried over anhydrous Na2S04 and concentrated under vacuum to give the crude product which was purified by column chromatography (100-200 silica gel) using 0.1 % MeOH/CHCIs. The recovered product was crystallized with methanol (3 ml) to afford the title compound as yellow solid (32 mg, 20 %). IR (KBR) crnl 3430. 5, 2227.79, 1707.19, 1635.3, 1574.97, 1487.82, 1154.96. ^H NMR (300 MHz, CDCI3) 5 2.2 (m, 2 H), 2.7 (m, 2 H), 3.08 (s, 3 H), 3.0-3.15 (m, 4 H), 4.0 (s, 3 H), 4.2 (s, 3 H), 6.6 (s, 1 H), 6.9 (d, 1 H, J = 9.0 Hz), 7.0 (d, 1 H, J = 9.0 Hz), 7.3 (d, 1 H, J = 9.0 Hz), 7.4 (d, 1 H, J = 9.0 Hz), 8.4 (s, 1 H). Preparation of 2-Amino-6-(1-methoxy-9-methyl-6-nitro-9H-carbazol-4-yl)-5,6,7,8-tetrahydro-quinazoline-6-carbonitrile: To the solution of 1-(1-methoxy-9-methyl-6-nitro-9/-/-carbazol-4-yl)-4-oxo-cyclohexanecarbonitrile (250 mg, 0.663 mmol) in DMF (10 ml) was added DMF.DMA (176.5 pi, 1.326 mmol) at room temperature and the mixture was stirred at 110 °C for 2 hours. The reaction was monitored by TLC (5 % MeOH/CHCIa). The reaction mass was diluted with cold water (30 ml) and extracted with ethyl acetate (3 x 40 ml). The combine organic layer was washed with water (3 x 20 ml), dried over anhydrous Na2S04 and concentrated under vacuum to afford the crude enamine (270 mg) intermediate which was directly treated with guanidine hydrochloride (83 mg, 0.862 mmol) and sodium ethoxide (63 mg, 0.92 mmol) in ethanol (10 ml) at 75-80 "C for 1 hour. After completion of the reaction, [monitored by TLC (5 % MeOH/CHCIa)], the reaction mass was concentrated under vacuum and purified by column chromatography (100-200 silica gel) using CHCI3 to give the title compound (92 mg, 32 %). mp: >314 "C. HPLC purity: 98.67 %. IR (KBR) cm"1 3468.04, 3312.02, 3187.42, 2935.89, 2227.41, 1629.23, 1572.96, 1509.21, 1480.40, 1312.09, 1275.08, 1076.14. ^H NMR (300 MHz, DMSO-ds) 5 2.28-3.0 (m, 4 H), 3.3 (d, 1 H, J = 15 Hz), 3.6 (d, 1 H, J = 15 Hz), 4.08 (s, 3 H), 4.29 (s, 3 H), 6.5 (s, 1 H), 7.2 (d, 1 H, J = 9.0 Hz), 7.3 (d, 1 H, J = 9.0 Hz),7.9 (d, 1 H, J = 9.0 Hz), 8.2 (s, 1 H), 8.4 (d, 1 H, J = 3.0 Hz), 9.2 (d, 1 H, J = 3.0 Hz). Example 29 Preparation of N-[9-(6-Cyano-5, 6,7, 8-tetrahyclro-quinazolin-6-yl)-6-difluoro-methoxy-dibenzofuran-2-yl]-methane sulfonamide Step 1: Preparation of 1-(-4-difluoromethoxy-8-nitro-dibenzofuran-1-yl)-4-oxo-cyclohexane carbonitrile A solution of intermediate 7 (0.350gm, 0.0004mole) and anhydrous potassium carbonate (0.188gm, 0.0013mole) in dry dimethylformamide (5ml) was stirred at room temperature for 10 minutes. Chlorodifluoromethane gas was purged in to the reaction mixture for 45 minutes and then the reaction mixture was allowed to stir for 18 hours. After completion of reaction, reaction mass was diluted with water (30ml) and extracted with ethyl acetate (3 X 30ml). The combined organic layer was washed with water, dried over sodium sulfate, filtered and concentrated under vacuum to obtain the title compound (0.158gm, yield-87%) as a yellow colored solid. ^H NMR (300 MHz, CDCI3) 6 2.31-2.40 (m, 2H), 2.73-2.88 (m, 2H), 2.95-2.98 (m, 2H), 3.03-3,22 (m, 2H), 6.83 (t, J = 72 Hz, 1H), 7.37 (d, J = 8.6 Hz, 1H), 7.48 (d, J = 8.2 Hz, 1H), 7.83 (d, J= 9.1Hz, 1H), 8.54 (d, J= 9.2 Hz, 1H), 9.28 (s, 1H) Step 2: Preparation of 1-(-4-difluoromethoxy-8-nitro-dlbenzofuran-1-yl)-3-dimethyl-atninomethylene-4-oxo-cyclohexane carbonitrile To a solution of step 1 (0.160g, 0.0003mole) in benzene (25ml) and 2 drops of triethylamine was added N,N- dimethylformamide dimethylacetal (0.08ml, O.QOOSmole) at room temperature under nitrogen. Reaction mixture was heated to reflux. Methanol was removed azeotropically using benzene as a solvent by Dean and Stark apparatus and added fresh benzene (40ml) and repeated the same operation until the starting material was absent by TLC. After completion of reaction, reaction mass was evaporated under vacuum to obtain the title compound in crude product as a brown color residue (0.0150gm), taken as such for the next step without purification. Step 3: Preparation of 6-(-4-difluoromethoxy-8-nitro-diben20furan-1-yl)-5, 6,7, 8- tetrahydro-quinazolin-6-yl)-6-carbonitrile A solution of crude compound of step 2 (0.150gm, 0.0003) and dry dimethylformamide (5ml) was added Formamidine HCI ( 0.029gm, 0.00036mole) at room temperature and then the reaction mixture heated to 140°C and maintained at 140°C for 2 hours. After completion of reaction, reaction mass was diluted with water (20ml) and extracted with ethyl acetate (3 X 30ml). The combined organic layer was washed with water, dried over sodium sulfate, filtered and concentrated under vacuum to obtain the title compound (0.038gm, yield-26,5%) as a yellow color solid. 'H NMR (300 MHz, DMSO-cfe) S 2.68-3.20 (m, 4H), 3.71 (d, J = 16 Hz, 1H), 3.90 (d, J = 16 Hz, 1H), 7.55 (t, J= 73 Hz, 1H), 7,57 (d, J= 8.3 Hz,1H), 7.66 (d, J=8.Z Hz, 1H), 8.20 (6.J = 9.1Hz, 1H), 8.60 (dd, J=9.2Hz, 1.9H2, 1H), 8.78 (s, 1H), 9.07 (s, 1H), 9.14 (d, J= 1.8 Hz, 1H), Step 4: Preparation of 6-(8-Amino-4-difluoromethoxy-dibenzofuran-1-yl)-5, 6,7, 8- tetrahydro-quinazolin-6-yl)-6-carbonitrile A solution of compound of step 3 (0.017gm, 0.038mmoles) in ethyl acetate (3ml) was added catalytic quantity of Raney Nickel and then hydrogenated under hydrogen with balloon pressure over a period of 12 hours. After completion of reaction, the reaction mixture was filtered through celite bed and concentrated under vacuum to obtain the title compound (0.014gm, yield-88 %) 'H NMR (300 MHz, CDCI3) 6 2.63-3,16 (m, 4H), 3.47 (d, J = 16 Hz, 1H), 3.84 (d, J = ^6 Hz, 1H), 6.83 (t, J= 73 Hz, 1H), 6.84-7.08 (m, 3H), 7.40-7.50 (m, 2H), 8.61 (s, 1H), 9.11 (s, 1H) Step 5: Preparation of N-[9-(6-Cyano-5, 6,7, 8-tetrahydro-quinazolin-6-yl)-6-difluoro- methoxy-dibenzofuran-2-yl]-methane sulfonamide A solution of compound of step 4 (0.014gm, 0.034mmole) in dry tetrahydrofuran (2ml) was added pyridine (0.02ml, 0.24mmole) at 10°C. Reaction mixture was stirred for 10 minutes and was added methanesulfonyl chloride (0.01ml, 0.12mmole). Reaction mixture was allowed for stirring for 2 hours at room temperature. After completion of reaction, reaction mass was diluted with water (10ml) and extracted with ethyl acetate (3 X 30ml). The combined organic layer was washed with water dried over sodium sulfate, filtered and concentrated under vacuum. The crude was purified by column chromatography by using chloroform to obtain the title compound (0.012gm, yield-71.8 %) as a yellow colored solid. ^H NMR (300 MHz, DMSO-c/g) 5 2.91 (s, 3H), 3.00-3.35 (m, 4H), 3.70 (d, J = 16 Hz, 1H), 3.84 (d, J= 16 Hz, 1H), 745 (t, J = 73 Hz, 1H), 7,47-7.57 (m, 3H), 7.91 (d, J= 8.9 Hz, 1H), 8.24 (s, 1H), 8.72 (s, 1H), 9.06 (s, 1H), 10.06 (s, 1H). Example 30 Preparation of N-t9-(6-Cyano-5,6,7,8-tetrahydro-quinazolin-6-yl)-6-methoxy- dibenzofuran-2-yl]-methane sulfonamide Step 1: Preparation of 1-(-4-methoxy-8-nitro-dibenzofuran-1-yi)-4-oxo-cyclohexane carbonitrile A solution of intermediate 7 (0.840gm, 0.0024mole) and aniiydrous potassium carbonate (0.992gm, 0.0071 mole) in dry dimethylformamide (15ml) was stirred at room temperature for 15 minutes. To that added drop wise methyl iodide (0.23ml, 0.003mole) over a period of 10 minutes at room temperature, and then the reaction mixture was allowed to stir for 2 hours at room temperature. After completion of reaction, reaction mass was diluted with water (50ml) and extracted with ethyl acetate (3 X 75ml). The combined organic layer was washed with water, dried over sodium sulfate, filtered and concentrated under vacuum to obtain the title compound (0.700gm, yield-80%) as a yellow color solid. ^H NMR (300 MHz, DMSO-cfs) 8 2.44-2.58 (m, 4H), 2.83-2.88 (m, 4H), 4.06 (s, 3H), 7.38 (d, J= 8.6 Hz, 1H), 7.49 (d, J= 8.6 Hz, 1H), 8.10 (d, J= 9.1Hz, 1H), 8.52 (dd, J = 9.1Hz, 2.1Hz, 1H), 9.15(d, J= 1.9 Hz, 1H) Step 2: Preparation of 1-(-4-methoxy-8-nitro-diben20furan-1-yl)-3- dimethylaminomethylene-4-oxo-cyclohexane carbonitrile A solution of compound of step 1 (0.200g, 0.0005mole) in benzene (50ml) and 2 drops of triethylamine was added N,N- dimethylformamide dimethylacetal (0.1ml, O.OOOSmole) at room temperature under nitrogen. The reaction mixture was heated to reflux. Methanol was removed azeotropically using benzene as a solvent by Dean and Stark apparatus and added fresh benzene (40ml) and repeated the same operation until the starting material was absent by TLC. After completion of reaction, reaction mass was evaporated under vacuum to get desired crude product as a brown color residue (0.120gm), taken as such for the next step without purification. Step 3: Preparation of 6-(-4-methoxy-8-nitro-dibenzofuran-1-yl)-5, 6,7, 8-tetrahydro- quinazolin-6-yl)-6-carbonitrile To a solution of crude product obtained in step 2 (0.115gm, 0.0002 mole) in dry dimethylformamide (5ml) was added Formamidine.HCI (0.021gm, 0.00025mole) at room temperature and then the reaction mixture was heated to 140°C and maintained at 140°C for 2 hours. After completion of reaction, reaction mass was diluted with water (20ml) and extracted with ethyl acetate (3 X 30ml). The combined organic layer was washed with water, dried over sodium sulfate, filtered and concentrated under vacuum to obtain the title compound (0.033gm, yield-35.2%) as a yellow color solid. 'H NMR (300 MHz, DMSO-cfs) 5 2.93-3,18 (m, 2H). 3.21-3.48 (m, 2H), 3.67 (d, J = 16.6 Hz, 1H), 3.88(d, J= 16.6 Hz, 1H), 4.05 (s, 3H), 7.38 (d, J= 8.6 Hz, 1H), 7.46 (d, J= 8.6 Hz, 1H), 8.12 (d,J= 9.1Hz, 1H), 8,54 (dd,J= 9.1Hz, 2.1Hz, 1H), 8.78 (s, 1H), 9.06 (s, 1H), 9,1 (d, J = 1,9 Hz, 1H), Step 4: Preparation of 6-(8-Amino-4-methoxy-dibenzofuran-1-yl)-5, 6,7, 8-tetrahydro- quinazolin-6-yl)-6-carbonitrile To a solution of connpound of step 3 (O.OSOgm, 0.012mmole) in ethyl acetate (10ml) and methanol (1ml) was added catalytic quantity of Raney Nickel and then hydrogenated under hydrogen gas with balloon pressure over a period of 12 hours. After completion of reaction, the reaction mixture was filtered through celite bed and the filtrate was concentrated under vacuum to obtain the title compound (0.043gm, yield- 93 %) ^H NMR (300 MHz, DMSO-dg) 6 2.94-3.06 (m, 4H), 3.63 (d, J = 16,2 Hz, 1H), 3.80 (d, J = 16,2 Hz, 1H), 3.98 (s, 3H), 5,23 (s, 2H), 6.86 (d, J= 8,5 Hz, 1H), 7,15 (d, vy= 9 Hz, 1H), 7,29 (d, J= 8,6Hz, 1H), 7.38 (s, 1H), 7.47 (d, J= 8.5Hz, 1H), 8,74 (s, 1H), 9.04 (s, 1H), Step 5: Preparation of N-[9-(6-Cyano-5, 6,7, 8-tetrahydro-quinazolin-6-yl)-6-methoxy- dibenzofuran-2-yl]-methane sulfonamide To a solution of compound of step 4 (0.040gm, O.OIOmmole) in dry tetrahydrofuran (3ml) was added pyridine (0.1ml, 0,10mmole) at 10°C. The reaction mixture was stirred for 10 minutes and was added methane sulfonyl chloride (0.01 mi, 0.13mmole). The reaction mixture was allowed for stirring for 2 hours at room temperature. After completion of reaction, reaction mass was diluted with water (10ml) and extracted with ethyl acetate (3 X 30ml). The combined organic layer was washed with water dried over sodium sulfate, filtered and concentrated under vacuum. The crude was purified by column chromatography using chloroform as an eluent to obtain the title compound (0,018gm, yield-37.1 %) as a yellow color solid. ^H NMR (300 MHz, CDCI3) 6 2.52-2,63 (m, 1H), 2,95-3.07 (m, 1H), 3.10 (s, 3H), 3.07-3,16 (m, 1H), 3.49-3.56 (m, 2H), 3.85 (d, J= 16,4 Hz, 1H), 4,09 (s, 3H), 6.82 (s, 1H), 7.01 (d, J = 8,6Hz, 1H), 7.22-7.33 (m, 2H), 7.70 (d, J= 8.8Hz, 1H), 8,28 (s, 1H), 8,64 (s, 1H), 9.10 (s, 1H) Preparation of 1 -(4-Methoxy-8-trifluoromethyl-dibenzof uran-1 -yl)-4-oxo-cyclohexane-caronitrile To a solution of intermediate 8 (3.4 gm, 0.0076 moles) in dimethyl sulphoxide (DMSO)(10 ml), was added water(1 ml), sodium chloride (2.9 gm, 0.049 moles) and then the reaction mass was heated to 140°C, and maintained at140°C for 5 hrs. After completion of reaction, reaction mixture was brought to room temperature and quenched with cold water (50 ml). The mixture was then extracted with ethyl acetate (3 X 75 ml). The organic layers were collected, combined dried over anhydrous sodium sulfate and concentrated under vacuum. The crude was purified by column chromatography by using 5-10% ethyl acetate-hexane to obtain the title compound (1.9 gm, yield 65 %) as a yellow color solid. 'H NMR (300 MHz, CDCI3) 6 2.27-2.38 (m, 2H), 2.68-2.74 (m, 2H), 2.95-3.15 (m, 4H), 4.10 (s, 3H), 7.06 (d, J = 8.6 Hz, 1H), 7.30 (d, J= 8.6 Hz, 1H), 7.81-7.82 (m, 2H), 8.58 (s 1H) MS(M*+1):388 Preparation of 5-(4-IVIethoxy-8-trifluoromethyl-dibenzofuran-1-yl)-3-oxo-3, 3a,4,5,6,7-hexahydro-2H-indazole-5-carbonitrile A mixture of intermediate 8 (0.050 gm, 0.0001 mole), hydrazine hydrate (0.01 ml, 0.0002 mole) and triethylamine (0.04 ml, 0.0003 mole) in methanol (5 ml) was stirred at reflux for 2 hrs. After completion of reaction, methanol was evaporated under vacuum and the residue was partitioned between Ethyl acetate (20ml) and water (20ml). The Ethyl acetate layer was washed with water followed by brine, and the organic layer was evaporated under vacuum to get obtain the title compound (0.042 gm, yield-87.8 %) as a Pale yellow solid. 'H-NMR (300MHz, DMSO-de) 5 2.50-2.54 (m, 1H), 2.67-2.89 (m, 4H), 3.05 (d, J = 15.4 Hz, 1H), 4.04 (s, 3H), 7.34 (d, J = 8.6 Hz, 1H), 7.47 (d, J = 8.6 Hz, 1H), 7.99 (d, J = 8.6, 1H), 8.09 (d, J=8.6 Hz, 1H), 8.48 (s, 1H), 9.64 (s, 1H), 11.32 (s, 1H) MS(M^+1):428 Preparation of 6-(4-Nlethoxy-8-trifluoromethyl-dibenzofuran-1-yl)-5,6,7,8-tetrahydro-quinazoline-6-carbonitrile A solution of crude intermediate 9 (0.420 gm, 0.0009) and dry DMF (5ml) was added Formamidine HCI ( 0.082gm, 0.001 moles) at RT and then RM heated to 140°C and maintained at 140°C for 2 hrs. After completion of reaction, reaction mass was diluted with water (20ml) and extracted with Ethyl acetate (3 X 30ml). The combined organic layer was washed with water dried over sodium sulfate, filtered and concentrated under vacuum to get the desired product (0.040 gm, yield-26.5%) as a yellow color solid. 'H-NMR (300MHz, CDCI3) 6 2.57-2.66 (m, 1H), 2.90-2.96 (m, 1H), 3.01-3.11 (m, 1H), 3.37-3.49 (m, IN), 3.54 (d, J = 16.6 Hz, 1H), 3.81 (d, J = 16.6 Hz, 1H), 4.10 (s, 3H), 7.03 (d, J = 8.4 Hz, 1H), 7.26 (d, J =8.4 Hz, 1H), 7.82 (m, 2H), 8.56-8.62 (m, 2H), 9.11 (s, 1H) Preparation of 2-Amino-6-(4-Methoxy-8-trifluoromethyl-dibenzofuran-1-yl)-5,6,7,8- tetrahydro-quinazoline-6>carbonitrile To a mixture of intermediate 9 (70 mg, 0.00015 moles), Guanidine HCI (20 mg, 0.0002 moles) and Sodium ethoxide (15 mg, 0.0002 moles) in 5 ml Ethanol, was heated at reflux for 2 hr. After completion of reaction, the mixture was cooled to room temperature and then evaporated the solvent under vacuum. The crude residue was purified by column chromatography to get 13 (30 mg, yield-81%) off white colored solid product. 'H-NMR (300MHz, DMSO-de) 5 2.50-2.60 (m, 1H), 2.75-2.85 (m, 2H), 2.90-3.10 (m, 1H), 3.30-3.40 (m, 1H), 3.55-3.70 (m, 1H), 4.04 (s, 3H), 6.53 (s, 2H), 7.34 (d, J= 8.6 Hz, IN), 7.42 (d, J = 8.6 Hz, 1H), 8.02 (d, J = 8.6Hz, 1H), 8.10 (d, J = 8.6 Hz, 1H), 8.17(s, 1H), 8.50 (s, 1H) Preparation of 6-(4-Methoxy-8-trifluoromethyl-dibenzofuran-1-yl)-2-methyl-5, 6, 7, 8-tetrahydro-quinazoline-6-carbonitrile To a mixture of intermediate 9 (70 mg, 0.00015 moles), Acetamidine HCI (37.4 mg, 0.0003 moles) and Sodium methoxide (30 mg, 0.0005 moles) in 3 ml Methanol, was stirred at RT for 3 hrs. After completion of reaction, reaction mixture was evaporated under vacuum. The crude residue was purified by column chromatography to get obtain the title compound (28 mg, yield-40.5%) off white colored solid product 'H-NMR (300MHz, DMSO-cfe) 5 2.65 (s, 3H), 2.79-3.20 (m, 4H), 3.60 (d, J = 16.4 Hz, 1H), 3.79 (d, J = 16.8 Hz, 1H), 4.04(s, 3H), 7.34(d, J=8.6H2, 1H), 7.41 (d, J =8.6 Hz, 1H), 8.06 (d, J=8,7Hz, 1H), 8.11 (d, J=8.7Hz, 1H), 8.51 (s, 1H), 8.64(s, 1H) In Vitro Assay Cell based cAMP reporter assay for screening PDE4 subtype specific inhibitors: HEK 293 cells were routinely maintained in T-25 cm2 flasks. One day prior to transfection, cells were seeded in 6 well cell culture plate (Corning) at a seeding density of 1.3 - 1.4 x 10® cells/well. Cells were transfected for 5 h using lipofectamine-2000, as per manufacturer instructions with total 4.0 pg of plasmid DNA/well. PDE4 expression plasmid in each well was 10%-50% of total plasmid DNA for respective subtype selective expression plasmids. Each well was transfected with PDE4 expression plasmid (10-50%), pCREluc plasmid (20-50%), pSV-i gal plasmid (20-30%) and empty vector to make up total DNA concentration. After 5 h of transfection, medium was removed and cells were trypsinized, counted and seeded in 96 well plates at a seeding density of 40000 cells/well in complete medium (DMEM with 10% FBS, 1x penicillin-streptomycin). Plate was incubated in CO2 incubator set to 37°C and 5% CO2 for overnight. Next day, cells were incubated with respective inhibitors for 30-45 minute, followed by stimulation with 5|JM forskolin for 4 h incubation in incubator. After 4 h, plate was taken out of incubator and medium was removed manually using pipette. Cells were lysed (120|jl/well) with 1x reporter lysis buffer (Promega, Inc. USA), for 15 min with moderate shaking on shaker at RT, followed by centrifugation at 4000 rpm for 8-10 min at 22°C. Supernatant was transferred (40MI, each) to White/Black luminescence plate and normal flat bottom plate, for Luciferase/Luminescence detection assay and 11-gal assay respectively. Luminescence readings were taken in a Perkin Elmer Victor Light. iw: Fresh blood was collected in Heparinzed tubes by venipuncture from male volunteers with consent. The subjects had no apparent inflammatory conditions and had not taken any NSAID for at least 4 days prior to blood collection. 487.5 |jl of triplicate of blood were pre-incubated with 2.5|jl of test compound at different concentration (0, 0.001, 0.003, 0.01, 0.03 0.1, 0.3, 1, 3, 10^JM) and vehicle (DMSO) at 37°C for 15 min, and this was followed by incubation blood with 10^il lipopolysaccharide (Final concentration 1|jg/ml) diluted in 0.1% bovine serum albumin diluted in phosphate buffer saline) for 24 hrs at 37°C. PBS was used as blanks. After the incubation period, the samples were centrifuged at 1500xg at 4 °C for 10 min. Plasma TNF-alpha was quantified ELISA (R&D System) We found that examples 29 and 33 able to inhibit 50% of LPS induce TNF-alpha production in Whole blood with concentration of 0.41 ± 0.02 and 0.092 ± 0.01 |JM (N=3) respectively. X represents 0, S or NR''; Y represents O, S, NR" or can be absent; X1 and X1 independently represent hydrogen, hydroxy, amino, nitro, cyano and optionally substituted groups selected from alkyl, alkoxy, C2-C6 alkenyl, C2-C6 alkynyl, alkyl hydroxy, alkyl halo, alkyl amino, alkenyl amino, alkenyl amino alkyl, guanidyl, ureidyl, CR1R®R7, CR1R1OR1 CR1R1C(0)R1 CR1R1C(0)C(0)OR1 CR1R®C(0)OR1 (CR1R1)nC(0)R', CR1R1C(0)NR1R1 CR'R1S(0),„R', CR1R'1N R1R1 CR1R'CN, CR1R'RQ, CR'R®NR1S(0)mR1 CR1R1N R1C(X)R', CR1R1NR'S(0LN R1'R', CR1R1NR1C(0)N R'R1 CR1R'1N R1C(0)C(0)OR1 CR1R1NR'C(S)N R1R1 CR1R®NR'C(NCN)N R1R1 NR1R1 NR1 NR1S(0)1,R1 NR''S(0)mNR1 NR1C(0)R1 NR1C(0)0R1 NR1C(0)N R'R1 NR1C(S)N R1R1 NR5C(0)NR1S(0UR', C(NR')R1 C(NNR1C(X)N R1R1)R1 C(NNR1S(0)1R1)R1 C(NR')N R1R®, C(NCN)SR1 C(NOR1)R1 C(0)OR1 C(0)NR1R1 C(0)N R1R1 C(0)NR1N R1R1 C(0)R', OR1 OC(0)R1 OC(0)N R1R', OS(0),„R1 SO2, SO3H, S(OLR1 S(R'), S(0)„NR1R'; or When X1 and X1 are adjacent to each other, they may together form a 4 to 7 membered cyclic group selected from substituted or unsubstituted cycioalkyi, substituted or unsubstituted aryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted heteroaryl. Nonlimiting examples of such cyclic group Include but not limited to pyrazole, imidazole, imidazolidine, triazole, tetrazole, pyrrolidine, pyrrole, thiophene, thiazole, oxazole, isoxazole, furan, tetrahydro thiophene, tetrahydrofuran, thiazolidine, oxazolidine, piperazine, morphollne, thiomorpholine, piperidine, pyridine, pyrazine, pyrimidine, pyridazine; X1 represent hydrogen, cyano, Ci1 alkyl, C2-4alkenyl, C2.4alkynyl, aikylhalo, nitro, alkylnitro, alkyl carboxy, alkylcarbonyl or tetrazole CH2NR1R1,CH20R*,C3-C4 cycio alkyl, 0R1 R1OR', NR1R', NR1R''N02, C(0)OR1 C(0)NR1R1 C(0)R' , CH2NHC(0)C(0) NH2, CHNR', CHN=OR1 NHCN, CH(CN)2, CH(CN)R1; X' represent O, NR1 N-OR', NCR'R®R1 N0R'°, NOR'R', NNR1R1 NCN, NNR1C(X)NR1R1 or '= X 4' may be dimethyl ketal, diethyl ketal, 1,3 dithiane, 1,3 dithiolane, 1,3 dioxane, 5,5-dimethyl-[1,3]dioxane or 1,3 dioxolane; or X and X" can form 5 to 7 membered cyclic group selected from substituted or unsubstituted cycloalkyi, substituted or unsubstituted aryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted heteroaryl. Nonlimiting examples of such cyclic group include but not limited to pyrazole, imidazole, imidazolidine, triazole, tetrazole, pyrrolidine, pyrrole, thiophene, thjazole, oxazole, isoxazole, furan, tetrahydro thiophene, tetrahydrofuran, thiazolidine, oxazolidine, piperazine, morphoiine, thiomorpholine, piperidine, pyridine, pyrazine, pyrimidine, pyridazine R1 and R1 are independently selected from hydrogen, hydroxyl, substituted or unsubstituted aikyi, aikoxy, aikenyl, alkynyl, aikyiamino ,aikyl hydroxy, alky! halo, nitro, amino, cyano, formyl, carboxy, carbamoyl, acyl, halogen, ureidyl, cycloalkyi, cycloalkenyi, aryl, heteroaryl, heterocyclyl, acylamino, alkanoylamino, CR1R1R'', CR1R1OR1 CR'1R1C(0)R1 CR1R'1C(0)C(0)0R', C R'R'C(0)OR', (CR1R1)nC(0)R1 C R1R''C(0)NR1R', C R1R®S(0)mR1 CR1R1NR1R1 CR'R1CN, CR1R1R1 CR1R1NR'S(0UR', CR'R1NR'C(X)R1 CR'R'NR1S(0)mNR'R1 CR'R'NR1C(0)NR'R1 CR1R®NR'C(0)C(0)0R1 CR'R1NR7C(S)N R1R1 CR1R®NR1C(NCN)N R1R1 NR'R®, NR1 NR1S(0)„R1 NR'S(0)1,NR1 NR'C(0)R1 NR*C(0)OR1 NR1C(0)NR1R1 NR'C(S)NR1R', NR1C(0)NR'S(0)n,R1 C(NR1)R1 C(NNR1C(X)N R1R1)R1 C(NN R1S(0)mR'1)R1 C(NR1)N R'■R1 C(NCN)SR1 C(N0R')R1, C(0)0 R1 C(0)N R1R1 C(0)N R1R®, C(0)NR1N R1R1 C(0)R1 0R1 0C(0)R1 OC(0)NR1R1 OS(0)mR', SO2, SO3H, S(0),1R1 S(R1 S(0UNR'R1; R''represents hydrogen, hydroxyl, alkyl, SO2CH3, S02PhCH3ora protecting group; R1, R®, R\ R1 may be independently selected from hydrogen, CrCe straight or branched alkyl, dialkyi, C2-C6 straight or branched aikenyl, aikyiamino, alkyl halo, alkyl hydroxy, acyl, aikoxy, carboxy, sulfonyl, sulfinyl, thio, sulfamido, amido, NH(CO)R'', nitro, amino ,halogens, hydroxy , ureidyl, guanidyl; or R' and R1 when attached to Nitrogen as NR'R° they may together with the nitrogen atom to which they are attached form a 5 to 7 membered Optionally substituted ,saturated, partially saturated or unsaturated ring optionally containing at least one additional heteroatom selected from O, NR1 or S; R' and R" independently represent hydrogen, hydroxyl, halo, cyano, substituted or unsubstituted alkyl, aikoxy, haloalkyi, CONH2, COOH; or R' and R" together with the carbon atoms to which they are attached form a C5 to Ce ring system selected from substituted or unsubstituted cycloalkyi, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl and the substitutions on the said cycloalkyi, heterocyclyl, aryl, heteroaryl include but not limited to halo, cyano, haloalkyi, amino, amido, NHS02Me and the like; r represents an integer ranging from 0, 1, 2 or 3; s represents an integer ranging from 0, 1 or 2; m represents an integer ranging from 0, 1 or 2; dotted line [—] inside the ring in general formula (I) represents an ojitional double bond; and their analogues, derivatives, tautomers, stereoisomers, enantiomers, diastereomers, polymorphs, pharmaceutically acceptable salts, pharmaceutically acceptable hydrates, pharmaceutically acceptable solvates, pharmaceutical compositions, N-oxides and bioisosteres. 2. A compound according to claim 1, wherein X is NR'' and Y is O 3. A compound according to claim 1, wherein X is O 4. A compound according to claim 1, wherein X1 is cyano 5. A compound according to claim 1, wherein R1 is selected from 6. A compound according to claim 1, wherein R1 is methyl 7. A compound according to claim 1, wherein R1 is difluoromethyl 8. A compound according to claim 1, wherein R and R" independently represent hydrogen 9. A compound according to claim 1, wherein R and R" together with the carbon atoms to which they are attached form a substituted phenyl ring 10. A compound according to claim 9, wherein the substitution on the phenyl ring NHS02Me 11. A compound according to claim 9, wherein the substitution on the phenyl ring CF3 12. A compound according to claim 1, wherein the compound is selected from 4,5,6,7-Tetrahydro-5-(1-methyl-1H-indQl-4-yl)-2H-indazole- 5-carbonitrile 4, 5, 6, 7-TetrahydrO'5-(1H-indol-4~yl)-2H-lndazole-5-carbonitrile 4,5,6,7-Tetrahydro-5-(7-methoxy-1H-indol-4-yl)-2H-indazole-5-carbonitrile 1-(7-Methoxy-1-methyl-1H-indol-4-yl)-4-oxocyclohexanecarbonitrile 4,5,6,7- Tetrahydro-5-(7-methoxy'1-methyl-1 H-indol-4-yl)-2H~indazole-5-carbonitrile 1-(7-methoxy-1 H-indol-4~yl)-4-oxocyclohexanecarbonitrile 4-(6-FluQro-1-methoxy-9-methyl-9H-carbazol-4-yl)-cyclohexanone 4'(1-methoxy-9'methyl-9H-carbazol-4-yl)-cyclohexanone 6-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-5,6,7,8-tetrahydroquinazoline-6- carbonitrile 2-Amino-6-(6-Fluoro-1~methoxy-9-methyl-9H-carbazol-4-yl)-5,6,7,8-tetrahydroquinazoline-6- carbonitrile 5-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-4,5,6,7'tetrahydro-2H-indazole-5' carbonltrile 5-(6-Fluoro-1-methoxy-9'methyl-9H-carbazol-4-yl)-4,5,6,7-tetrahydro-benzo[c]isoxazole-5- carbonitrile 6-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-2-methyl-5,6,7,8-tetrahydroquinazoline-6- carbonitrile 6-(1-methoxy-9-methyl-9H-carbazol-4-yl)-5,6,7,8-tetrahydmquinazoline-6-carbonitrile 2-Amino-6-(1-methoxy-9-methyl-9H-carbazol-4-yl)-5,6,7,8-tetrahydroquinazoline-6- carbonitrile 5-(1-methoxy-9-methyF9H-carbazol-4-yl)-4,5,6,7-tetrahydro-2H-indazole-5-carbonitrile 5-(1-methoxy-9-methyl-9H-carbazol-4-yl)-4,5,6,7-tetrahydm-benzo[c]isoxazole-5-carbonitrile 6-(6-Fluoro-1-methoxy-9-methyl-9H'Carbazol-4-yl)'4-oxo-3,4,5,6,7,8'hexahydroquinazoline- 6-carbonitrile 2-Amino-6-(6-Fluoro-1-methoxy-9~methyl-9H-carbazol-4-yl)-4-oxo-3,4,5,6,7,8- hexahydroquinazoline'6-carbonitrile 5-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol-4-yl)-3~oxo-3,3a,4,5,6,7-hexahydro-2H- indazole-5-carbonitrile 6-(6-Fluoro-1-methoxy-9-methyl-9H-carbazol'4-yl)-2-methyl-4-oxO'3,4,5,6,7,8- hexahydroquinazoline-6-carbonitrile 2-Amino-6-(1-methoxy-9-methyl-9H-carbazol-4-yl)-4-oxo-3,4,5,6,7,8-hexahydroqulnazoline- 6'Carbonitrile 5-(1-methoxy-9-methyl-9H-carbazol-4-yl)-3-oxo-3,3a, 4,5,6,7-hexahydro-2H-indazole-5- carbonitrile 1-(1-Methoxy-9-methyl-6-nitro-9H-carbazol-4-yl)-4-oxo-cyclohexanecarbonitrile 6'(1'Methoxy-9-methyl-6-nitro-9H-carbazol-4-yl)-5,6,7,8-tetrahydro-quinazoline-6-carbonitrile N-[5-(6-CyanO'5,6,7,8-tetrahydro-quinazolin-6-yl)-8-methoxy-9-methyl-9H-carbazol-3-yl]- methanesulfonamide N-[5-(1-Cyano-4-oxo-cyclohexyl)-8-methoxy-9-methyl-9H-carbazol-3-yl]-methanesulfonamide 2-Amino-6-(1-methoxy-9-methyl-6-nitro-9H-carbazol-4-yl)-5,6,7,8-tetrahydro-quinazoline-6- carbonitrile N-[9-(6-Cyano-5, 6,7, 8-tetrahydro-quinazolln-6-yl)-6-dlfluoromethoxy-dibenzofuran-2-yl]- methane sulfonamide N-[9-(6'Cyano-5, 6,7, 8-tetrahydro-quinazolin-6-yl)-6-methoxy-dibenzofuran-2-yl]-methane sulfonamide 6-(4-Methoxy-8-trifluoromethyl-dibenzofuran~1-yl)-5,6,7,8-tetrahydro-quinazoline-6- carbonitrile 1-(4-Methoxy-8-trifluoromethyl-dibenzofuran-1-yl)-4-oxo-cyclohexanecaronitrile 5-(4-Methoxy-8-trifluoromethyl-dibenzofuran'1-yl)-3-oxo-3, 3a,4,5,6,7-hexahydro-2H- indazole-5-carbonitrlle 2-A mino-6-(4-Methoxy-8-trifluoromethyl-dibenzofuran-1 -yl)-5,6,7,8-tetrahydro-quinazoline-6- carbonithle 6-(4-Methoxy-8-trifluoromethyl-dibenzofuran-1-yl)-2-methyl-5, 6, 7, 8-tetrahydro-quinazoline- 6-carbonitrile 13. A process for preparing a compound of general formula (I) or a pharmaceutically acceptable salt, pharmaceutically acceptable solvate, enaontlomer, diastereiomer or N-oxide thereof comprising at least one of the steps of a. preparing the compound of general formula E wherein X1, R' and R" are as General Formula (I) e. alternately, the compound of general formula G is converted to compound of general formula I using dimethylformamide dimethylacetal in suitable solvent such as benzene I f. compound of general formula I is then converted to compound of general formula (I) wherein R1 is as defined in claim 4 by using suitable reagent such as hydrazone hydrate or phenyl hydrazine in the presence of suitable solvent such as ethanol 14. A pharmaceutical composition comprising a therapeutically effective amount of a compound of general formula (I) according to claim 1 or a pharmaceutically acceptable salt thereof. 15. A pharmaceutical composition according to claim 12, or a pharmaceutically acceptable salt thereof for use as a Phosphodiesterase 4 (PDE IV) inhibitor. 16. A method for treating an inflammatory disease, disorder or condition characterized by or associated with an excessive secretion of TNF-a and Phosphodiesterase 4 (PDE IV), which comprises administering to a subject in need thereof a therapeutically effective amount of a compound according to claim 1 17. The method according to claim 14, wherein said inflammatory conditions and disorders are chosen from the group comprising asthma, COPD, allergic rhinitis, allergic conjunctivitis, respiratory distress syndrome, chronic bronchitis, nephritis, rheumatoid spondylitis, osteoarthritis, atopic dermatitis, eosinophilic granuloma, psoriasis, rheumatoid septic shock, ulcerative colitis, multiple sclerosis, chronic inflammation, Crohn's syndrome and central nervous system(CNS) disorders 18. The Use of the compound according to claims 1 to 10, in a medicament for the treatment of inflammatory conditions and disorders are chosen from the group comprising asthma, COPD, allergic rhinitis, allergic conjunctivitis, respiratory distress syndrome, chronic bronchitis, nephritis, rheumatoid spondylitis, osteoarthritis, atopic dermatitis, eosinophilic granuloma, psoriasis, rheumatoid septic shock, ulcerative colitis, multiple sclerosis, chronic inflammation, Crohn's syndrome and , central nervous system(CNS) disorders.