CROSS REFERENCE TO RELATED APPLICATION [1] This application claims the priority benefits of IN Provisional Patent Applciation No. 202111004177, filed on January 30, 2021; disclosures of which are incorporated herein by reference in its entireties. FIELD OF THE INVENTION [2] The present invention generally relates to compounds having Checkpoint kinase-1 (CHK-1) inhibitory activity, to the use of such compounds in the treatment of proliferative disorders, such as cancer; Pulmonary Arterial Hypertension (PAH) and Idiopathic Pulmonary Fibrosis (IPF). The invention also provides method of synthesis of said compounds, method of using said compounds, pharmaceutical compositions comprising said compounds and method of using thereof. BACKGROUND OF THE INVENTION [3] A wide range of cancer chemotherapeutic agents act through DNA damaging pathway to induce DNA damage causing tumor growth inhibition. However, these chemotherapeutic agents lead to cell cycle arrest by induction of checkpoints at either S-phase or G2/M boundary. The G2 arrest allows the cell time to repair the damaged DNA before entering mitosis. Checkpoint kinase-1 (CHK-1) and an unrelated serine/threonine kinase, Checkpoint kinase-2 (CHK-2), play a central role in arresting the cell cycle at the G2-M boundary (O'Connell et al EMBO J (1997) vol. 16 p. 545-554). CHK-1 and/or CHK-2 induce this checkpoint by phosphorylating serine 216 of the CDC25 phosphatase, inhibiting the removal of two inactivating phosphates on cyclin dependent kinases (CDKs) (Zheng et al Nature (1998) vol. 395 p. 507-510). Another overlapping pathway mediated by p53 also elicits cycle arrest in response to DNA-damage. However, p53 is mutationally inactivated in many cancers, resulting in a partial deficiency in their ability to initiate a DNA-repair response. If CHK-1 activity is also inhibited in p53-negative cancers, all ability to arrest and repair DNA in response to DNA-damage is removed resulting in mitotic catastrophe and enhancing the effect of the DNA damaging agents (Konarias et al. Oncogene (2001) vol. 20 p 7453-7463, Bunch and Eastman Clin. Can. Res. (1996) vol. 2 p 791-797, Tenzer and Pruschy Curr. Med Chem (2003) vol 3 p 35-46). [4] CHK-1 inhibition, therefore, represents a novel therapeutic strategy to increase the lethality of DNA-damaging chemotherapeutic drugs in p53 pathway defective cancers. Abrogation of the remaining intact checkpoint should result in increased tumor cell death. CHK-1 inhibitors have demonstrated potentiation of a range of cytotoxic chemotherapy drugs both in vitro and in a range of pre-clinical models of human cancer including gemcitabine, irinotecan, cytarabine, and cisplatin. This "synthetic lethality" approach should increase the therapeutic activity of the chemotherapeutic drug without increasing the systemic toxicity as normal cells should remain protected by their functional p53 pathway. CHK-1 inhibitors have, therefore, the potential to be combined with a wide range of cytotoxic chemotherapeutic agents for the treatment of a diverse selection of human cancers. [5] Further, excessive and sustained proliferation, resistance to apoptosis by fine tuning of cell cycle and DNA repair machinery are few of the causative mechanisms of cancer, Pulmonary Arterial Hypertension (PAH) and Idiopathic Pulmonary Fibrosis (IPF). PAH is a devastating disease accompanied with progressive vascular remodeling of distal pulmonary arteries leading to concomitant elevation of pulmonary artery pressure, perivascular inflammation, fibrotic changes, right ventricular hypertrophy, and death (Bourgeois et.al., Arterioscler Thromb Vase Biol. 2019;39:1667-1681). It is a concurrent complication of Idiopathic Pulmonary Fibrosis and affects its survival, functional status and progression, however no treatment other than lung transplantation are currently available (Wu et.al., Am J Respir Crit Care Med 2020;201:A2499). Besides genetic predisposition, a number of epigenetic factors such as oxidative stress and generation of reactive oxygen species cause DNA damage in pulmonary artery smooth muscle cells (PAH-PASMCs) and alter the cellular functions similar to cancer cells. Since DNA repair machinery has been targeted successfully to delineate the underlying molecular mechanisms of cancer and a wide range of chemotherapeutic agents are being explored, which act through DNA damaging pathway to induce DNA damage causing tumor growth inhibition, similar approach could be adopted for PAH-IPF. In cancer, these chemotherapeutic agents lead to cell cycle arrest by induction of checkpoints at either S-phase or G2/M boundary, wherein, the G2 arrest allows the cell time to repair the damaged DNA before entering mitosis. Checkpoint kinase-1 (CHK-1) and Checkpoint kinase-2 (CHK-2), serine/threonine kinases, are DNA damage sensors and critical regulators of DNA repair and cell cycle progression. They are upregulated in cancer cells and play a central role in arresting the cell cycle at the G2-M boundary to facilitate DNA repair (O'Connell et al EMBO J (1997) vol. 16 p. 545-554). CHK-1 and/or CHK-2 induce this checkpoint by phosphorylating serine 216 of the CDC25 phosphatase, inhibiting the removal of two inactivating phosphates on cyclin dependent kinases (CDKs) (Zheng et al Nature (1998) vol. 395 p. 507-510). In PAH-IPF, proliferating PAH-PASMCs show increased levels of y-H2AX and pRPA32, markers for DNA damage/replication stress and also display enhanced expression and activation of CHKl. Moreover, pharmacological inhibition of CHKl improves PAH in clinically relevant rat models suggesting that CHKl inhibition could also be an attractive therapeutic option for PAH (Bourgeois et.al., Arterioscler Thromb Vase Biol. 2019;39:1667-1681). However, in cancer, another overlapping pathway mediated by p53 also elicits cycle arrest in response to DNA-damage. In many cancers, p53 is mutationally inactivated resulting in a partial deficiency in their ability to initiate a DNA-repair response. If CHK-1 activity is also inhibited in p53-negative cancers, all ability to arrest and repair DNA in response to DNA-damage is removed resulting in mitotic catastrophe and enhancing the effect of the DNA damaging agents (Konarias et al. Oncogene (2001) vol. 20 p 7453-7463, Bunch and Eastman Clin. Can. Res. (1996) vol. 2 p 791-797, Tenzer and Pruschy Curr. Med Chem (2003) vol 3 p 35-46). [6] Various attempts have been made to develop CHK-1 kinase inhibitors. For example, US10000481B2 (Vernalis) disclose lH-pyrrolo[2,3-B] pyridine derivatives compounds as CHK-1 kinase inhibitors. US10010547B2 (Cascadian Therapeutics) discloses pyrazol amino pyrazine derivatives as kinase inhibitors. WO/2018/086546Al (Zhejiang university) disclose 2-polysubstituted aromatic ring-pyrimidine derivatives as CHK-1 inhibitors. Some small molecule inhibitors of CHK-1 (Prexasertib/LY2606368, LY2603618 and SRA737) are currently in Phase I/II clinical evaluation in combination with gemcitabine, pemetrexed, fludarabine, cytarabine, and cisplatin. [7] The main features of IPF-PH are excessive proliferation and resistance to apoptosis of fibroblasts and pulmonary arterial (PA) smooth muscle cells (PASMC) leading to aberrant accumulation of extracellular matrix in parenchyma and extensive vascular remodeling. It can be hypothesized that CHK1/2, which is upregulated and activated in IPF-PH contributes to fibrotic and vascular lesions in IPF-PH. This is associated with DNA repair initiation enzyme yH2Ax which in turn correlates with PAH remodeling and fibrosis scores. The increase in DNA repair in IPF is associated with a significant upregulation of CHK1 and CHK2 in the lungs and distal PA of IPF patients and it was mainly localized within PASMC and fibrotic lesions. Some of the drugs which target proliferation could be protective against PAH and since CHK1 activation in PAH-PASMCs is known to be a decisive event in the initiation of pulmonary vascular remodeling in PAH, it could be a potential therapeutic target for PAH-IPF (Satoh et.al., Int J Mol Sci. 2018;19, Bourgeois et.al., Arterioscler Thromb Vase Biol. 2019;39:1667-1681). [8] Activation of the ATR-CHK1 signaling in PAH-PASMCs and significant therapeutic effects observed by the inhibition of this axis in animal models mimicking PAH reflects indicate that CHK1 may represent a new therapeutic avenue for patients with PAH. This would block or reversing pulmonary vascular remodeling, a key pathological feature of PAH for which current approved therapies have limited efficacy. Moreover, therapeutic effects observed for cancer by inhibition of CHK1 also highlight a continuing need for developing new CHK-1 inhibitors with pharmacokinetic and pharmacodynamic properties making them suitable for use as pharmaceutical agents. The object of the present invention is to provide such pharmaceutical agents and treatments. [9] Thus, there remains a continuing need for developing new CHK-1 inhibitors with pharmacokinetic and pharmacodynamic properties making them suitable for use as pharmaceutical agents. The object of the present invention is to provide such pharmaceutical agents and treatments. SUMMARY OF THE INVENTION [10] In one aspect, the present invention provides a compound of formula (J): K *K A J> (RX)o-2 N N Xg H formula (J), or a salt, thereof, wherein Xi, X2, Q, A, L and Rx are as detailed herein. [11] In one aspect, the compound of formula (J) or a salt thereof, is a compound of formula (I) or a salt thereof, as detailed herein. [12] In one aspect, the compound of formula (J) or a salt thereof, is a compound of formula (IA) or a salt thereof, as detailed herein. [13] In some aspects, the compound of formula (IA) or a salt thereof, is any of the compounds of formula (IA-1) to (IA-10) or a salt thereof, as detailed herein [14] In one aspect, the compound of formula (J) or a salt thereof, is a compound of formula (IB) or a salt thereof, as detailed herein. [15] In some aspects, the compound of formula (IB) or a salt thereof, is any of the compounds of formula (IB-1) to (IB-10) or a salt thereof, as detailed herein [16] In one aspect, the compound of formula (J) or a salt thereof, is a compound of formula (II) or a salt thereof, as detailed herein. [17] In some aspects, the compound of formula (II) or a salt thereof, is any of the compounds of formula (Il-a) to (II-c) or a salt thereof, as detailed herein. [18] In one aspect, the compound of formula (J) or a salt thereof, is a compound of formula (III) or a salt thereof, as detailed herein. [19] In some aspects, the compound of formula (III) or a salt thereof, is any of the compounds of formula (Ill-a) to (III-c) or a salt thereof, as detailed herein. [20] In one aspect, the compound of formula (J) or a salt thereof, is a compound of formula (IV) or a salt thereof, as detailed herein. [21] In some aspects, the compound of formula (IV) or a salt thereof, is any of the compounds of formula (IV-a) to (IV-c) or a salt thereof, as detailed herein. [22] In one aspect, the compound of formula (J) or a salt thereof, is a compound of formula (V) or a salt thereof, as detailed herein. [23] In some aspects, the compound of formula (V) or a salt thereof, is any of the compounds of formula (V-a) to (V-f) or a salt thereof, as detailed herein. [24] In one aspect, the compound of formula (J) or a salt thereof, is a compound of formula (VI) or a salt thereof, as detailed herein. [25] In some aspects, the compound of formula (VI) or a salt thereof, is any of the compounds of formula (Vl-a) to (Vl-f) or a salt thereof, as detailed herein. [26] In one aspect, the compound of formula (J) or a salt thereof, is a compound of formula (VII) or a salt thereof, as detailed herein. [27] In some aspects, the compound of formula (VII) or a salt thereof, is any of the compounds of formula (VH-a) to (VH-f) or a salt thereof, as detailed herein. [28] In one aspect, the compound of formula (J) or a salt thereof, is a compound of formula (VIII) or a salt thereof, as detailed herein. [29] In some aspects, the compound of formula (VIII) or a salt thereof, is any of the compounds of formula (VHI-a) to (Vlll-f) or a salt thereof, as detailed herein. [30] In some another aspect, the present invention provides method of treating a disease or disorder associated with this CHK kinase enzymes, more specifically CHK-1 kinase enzymes in an individual in need thereof, wherein the method comprises administering to the individual an effective amount of a compound of the present invention (collectively, a compound of formula (J), (I), (IA), (IA-1) to (IA-10), (IB) , (IB-1) to (IB-10), (II), (Il-a) to (II-c), (III), (Ill-a) to (III-c), (IV), (IV-a) to (IV-c), (V), (V-a) to (V-f), (VI), (Vl-a) to (VI-f)) (VII), (VH-a) to (VII-f), (VIII), (VHI-a) to (VHI-f) or a salt thereof. [31] In some another aspect, the present invention provides method of treating cancer in an individual in need thereof, wherein the method comprises administering to the individual an effective amount of a compound of the present invention (collectively, a compound of formula (J), (I), (IA), (IA-1) to (IA-10), (IB) , (IB-1) to (IB-10), (II), (Il-a) to (II-c), (III), (Ill-a) to (III-c), (IV), (IV-a) to (IV-c), (V), (V-a) to (V-f), (VI), (Vl-a) to (VI-f)) (VII), (VH-a) to (Vll-f), (VIII), (VHI-a) to (VHI-f), or a salt thereof. [32] In some another aspect, the present invention provides method of treating Idiopathic Pulmonary Fibrosis (IPF) in an individual in need thereof, wherein the method comprises administering to the individual an effective amount of a compound of the present invention (collectively, a compound of formula (J), (I), (IA), (IA-1) to (IA-10), (IB) , (IB-1) to (IB-10), (II), (Il-a) to (II-c), (III), (Ill-a) to (III-c), (IV), (IV-a) to (IV-c), (V), (V-a) to (V-f), (VI), (Vl-a) to (VI-f)) (VII), (VH-a) to (VH-f), (VIII), (VHI-a) to (VIII-f)), or a salt thereof. [33] In some another aspect, the present invention provides method of treating I Pulmonary Arterial Hypertension (PAH) in an individual in need thereof, wherein the method comprises administering to the individual an effective amount of a compound of the present invention (collectively, a compound of formula (J), (I), (IA), (IA-1) to (IA-10), (IB) , (IB-1) to (IB-10), (II), (Il-a) to (II-c), (III), (Ill-a) to (III-c), (IV), (IV-a) to (IV-c), (V), (V-a) to (V-f), (VI), (Vl-a) to (VI-f)) (VII), (VH-a) to (Vll-f), (VIII), (VHI-a) to (VIII-f)), or a salt thereof. [34] In some another aspect, the present invention provides method of treating a disease or disorder associated with this CHK kinase enzymes, more specifically CHK-1 kinase enzymes in an individual in need thereof, wherein the method comprises administering to the individual an effective amount of a compound of the present invention (collectively, a compound of formula (J), (I), (IA), (IA-1) to (IA-10), (IB) , (IB-1) to (IB-10), (II), (Il-a) to (II-c), (III), (Ill-a) to (III-c), (IV), (IV-a) to (IV-c), (V), (V-a) to (V-f), (VI), (Vl-a) to (VI-f)) (VII), (VH-a) to (VII-f), (VIII), (VHI-a) to (VIII-f)), or a salt thereof in combination with other therapeutic agents. [35] In some another aspect, the present invention provides pharmaceutical compositions, comprising a compound of the present invention (collectively, a compound of formula (J), (I), (IA), (IA-1) to (IA-10), (IB) , (IB-1) to (IB-10), (II), (Il-a) to (II-c), (III), (Ill-a) to (III-c), (IV), (IV-a) to (IV-c), (V), (V-a) to (V-f), (VI), (Vl-a) to (VI-f)) (VII), (VH-a) to (Vll-f), (VIII), (VHI-a) to (VIII-f)), or a salt thereof. [36] In some another aspect, the present invention provides method of treating a disease or disorder associated with this CHK kinase enzymes, or more specifically CHK-1 kinase enzymes in an individual in need thereof, wherein the method comprises administering to the individual an effective amount of a pharmaceutical composition comprising a compound of the present invention (collectively, a compound of formula (J), (I), (IA), (IA-1) to (IA-10), (IB) , (IB-1) to (IB-10), (II), (Il-a) to (II-c), (III), (Ill-a) to (III-c), (IV), (IV-a) to (IV-c), (V), (V-a) to (V-f), (VI), (Vl-a) to (VI-f)) (VII), (VH-a) to (Vll-f), (VIII), (VHI-a) to (VIII-f)), or a salt thereof. [37] In some another aspect, the present invention provides processes for preparing compounds and intermediates thereof disclosed in the present invention. DETAIL DESCRIPTION OF THE INVENTION Definitions [38] "Alkyl" refers to and includes saturated linear and branched univalent hydrocarbon structures and combination thereof, having the number of carbon atoms designated {i.e., C1-C10 means one to ten carbons). Particular alkyl groups are those having 1 to 20 carbon atoms (a "Ci-C2o alkyl"). More particular alkyl groups are those having 1 to 8 carbon atoms (a "Ci-C8 alkyl"), 3 to 8 carbon atoms (a "C3-C8 alkyl"), 1 to 6 carbon atoms (a "C1-C6 alkyl"), 1 to 5 carbon atoms (a "C1-C5 alkyl"), or 1 to 4 carbon atoms (a "C1-C4 alkyl"). Examples of alkyl include, but are not limited to, groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, sec-butyl, homologs and isomers of, for example, n-pentyl, n-hexyl, n-heptyl, n-octyl, and the like. [39] "Alkenyl" as used herein refers to an unsaturated linear or branched univalent hydrocarbon chain or combination thereof, having at least one site of olefinic unsaturation {i.e., having at least one moiety of the formula C=C) and having the number of carbon atoms designated {i.e., C2-Ci0 means two to ten carbon atoms). The alkenyl group may be in "cis" or "trans" configurations, or alternatively in "E" or "Z" configurations. Particular alkenyl groups are those having 2 to 20 carbon atoms (a "C2-C2o alkenyl"), having 2 to 8 carbon atoms (a "C2-C8 alkenyl"), having 2 to 6 carbon atoms (a "C2-C6 alkenyl"), or having 2 to 4 carbon atoms (a "C2-C4 alkenyl"). Examples of alkenyl include, but are not limited to, groups such as ethenyl (or vinyl), prop-1-enyl, prop-2-enyl (or allyl), 2-methylprop-1-enyl, but-1-enyl, but-2-enyl, but-3-enyl, buta-l,3-dienyl, 2-methylbuta-l,3-dienyl, homologs and isomers thereof, and the like. [40] "Alkylene" as used herein refers to the same residues as alkyl, but having bivalency. Particular alkylene groups are those having 1 to 6 carbon atoms (a "Ci-C6 alkylene"), 1 to 5 carbon atoms (a "C1-C5 alkylene"), 1 to 4 carbon atoms (a "C1-C4 alkylene") or 1 to 3 carbon atoms (a "C1-C3 alkylene"). Examples of alkylene include, but are not limited to, groups such as methylene (-CH2-), ethylene (-CH2CH2-), propylene (-CH2CH2CH2-), butylene (-CH2CH2CH2CH2-), and the like. [41] "Alkynyl" as used herein refers to an unsaturated linear or branched univalent hydrocarbon chain or combination thereof, having at least one site of acetylenic unsaturation (i.e., having at least one moiety of the formula C=C) and having the number of carbon atoms designated (i.e., C2-Cio means two to ten carbon atoms). Particular alkynyl groups are those having 2 to 20 carbon atoms (a "C2-C20 alkynyl"), having 2 to 8 carbon atoms (a "C2-C8 alkynyl"), having 2 to 6 carbon atoms (a "C2-C6 alkynyl"), or having 2 to 4 carbon atoms (a "C2-C4 alkynyl"). Examples of alkynyl include, but are not limited to, groups such as ethynyl (or acetylenyl), prop-1-ynyl, prop-2-ynyl (or propargyl), but-1-ynyl, but-2-ynyl, but-3-ynyl, homologs and isomers thereof, and the like. [42] "Aryl" refers to and includes polyunsaturated aromatic hydrocarbon groups. Aryl may contain additional fused rings (e.g., from 1 to 3 rings), including additionally fused aryl, heteroaryl, cycloalkyl, and/or heterocyclyl rings. In one variation, the aryl group contains from 6 to 14 annular carbon atoms. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, biphenyl, and the like. [43] "Carbonyl" refers to the group C=0. [44] "Cycloalkyl" refers to and includes cyclic univalent hydrocarbon structures, which may be fully saturated, mono- or polyunsaturated, but which are non-aromatic, having the number of carbon atoms designated (e.g., Ci-Cio means one to ten carbons). Cycloalkyl can consist of one ring, such as cyclohexyl, or multiple rings, such as adamantly, but excludes aryl groups. A cycloalkyl comprising more than one ring may be fused, spiro or bridged, or combinations thereof. A preferred cycloalkyl is a cyclic hydrocarbon having from 3 to 13 annular carbon atoms. A more preferred cycloalkyl is a cyclic hydrocarbon having from 3 to 8 annular carbon atoms (a "C3-C8 cycloalkyl"). Examples of cycloalkyl include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 1-cyclohexenyl, 3-cyclohexenyl, cycloheptyl, norbornyl, and the like. [45] "Halo" or "halogen" refers to elements of the Group 17 series having atomic number 9 to 85. Preferred halo groups include fluoro, chloro, bromo and iodo. Where a residue is substituted with more than one halogen, it may be referred to by using a prefix corresponding to the number of halogen moieties attached, e.g., dihaloaryl, dihaloalkyl, trihaloaryl etc. refer to aryl and alkyl substituted with two ("di") or three ("tri") halo groups, which may be but are not necessarily the same halo; thus 4-chloro-3-fluorophenyl is within the scope of dihaloaryl. An alkyl group in which each hydrogen is replaced with a halo group is referred to as a "perhaloalkyl." A preferred perhaloalkyl group is trifluoroalkyl (-CF3). Similarly, "perhaloalkoxy" refers to an alkoxy group in which a halogen takes the place of each H in the hydrocarbon making up the alkyl moiety of the alkoxy group. An example of a perhaloalkoxy group is trifluoromethoxy (-OCF3). [46] "Heteroaryl" refers to and includes unsaturated aromatic cyclic groups having from 1 to 10 annular carbon atoms and at least one annular heteroatom, including but not limited to heteroatoms such as nitrogen, oxygen and sulfur, wherein the nitrogen and sulfur atoms are optionally oxidized, and the nitrogen atom(s) are optionally quaternized. A heteroaryl group can be attached to the remainder of the molecule at an annular carbon or at an annular heteroatom. Heteroaryl may contain additional fused rings (e.g., from 1 to 3 rings), including additionally fused aryl, heteroaryl, cycloalkyl, and/or heterocyclyl rings. Examples of heteroaryl groups include, but are not limited to imidazolyl, pyrrolyl, pyrazolyl, 1,2,4-triazolyl, thiophenyl, furanyl, thiazolyl, isothiazolyl, thiadiazolyl, oxazolyl, isoxazolyl, oxadiazolyl, pyridyl, pyrimidyl, pyridazinyl or pyrazinyl, and the like. [47] "Heterocycle" or "heterocyclyl" refers to a saturated or an unsaturated non-aromatic group having from 1 to 10 annular carbon atoms and from 1 to 4 annular heteroatoms, such as nitrogen, sulfur or oxygen, and the like, wherein the nitrogen and sulfur atoms are optionally oxidized, and the nitrogen atom(s) are optionally quaternized. A heterocyclyl group may have a single ring or multiple condensed rings, but excludes heteroaryl groups. A heterocycle comprising more than one ring may be fused, spiro or bridged, or any combination thereof. In fused ring systems, one or more of the fused rings can be aryl or heteroaryl. Examples of heterocyclyl groups include, but are not limited to, aziridinyl, azetidinyl, oxetanyl, morpholinyl, thiomorpholinyl, azepanyl tetrahydropyranyl, dihydropyranyl, piperidinyl, piperazinyl, pyrrolidinyl, thiazolinyl, thiazolidinyl, tetrahydrofuranyl, tetrahydrothiophenyl, and the like. [48] "Oxo" refers to the moiety =0. [49] "CHK" refers to Checkpoint kinase, which includes CHK-1 and CHK-2. CHK refers herein specifically to CHK-1. [50] "Optionally substituted" unless otherwise specified means that a group may be unsubstituted or substituted by one or more (e.g., 1, 2, 3, 4 or 5) of the substituents listed for that group in which the substituents may be the same of different. In one embodiment, an optionally substituted group has one substituent. In another embodiment, an optionally substituted group has two substituents. In another embodiment, an optionally substituted group has three substituents. In another embodiment, an optionally substituted group has four substituents. In some embodiments, an optionally substituted group has 1 to 2, 2 to 5, 3 to 5, 2 to 3, 2 to 4, 3 to 4, 1 to 3, 1 to 4 or 1 to 5 substituents. [51] A "pharmaceutically acceptable carrier" refers to an ingredient in a pharmaceutical formulation, other than an active ingredient, which is nontoxic to a subject. A pharmaceutically acceptable carrier includes, but is not limited to, a buffer, excipient, stabilizer, or preservative. [52] As used herein, "treatment" or "treating" is an approach for obtaining beneficial or desired results including clinical results. For example, beneficial or desired results include, but are not limited to, one or more of the following: decreasing symptoms resulting from the disease, increasing the quality of life of those suffering from the disease, decreasing the dose of other medications required to treat the disease, delaying the progression of the disease, and/or prolonging survival of individuals. In reference to cancers or other unwanted cell proliferation (idiopathic pulmonary fibrosis (IPF)), beneficial or desired results include shrinking a tumor (reducing tumor size); decreasing the growth rate of the tumor (such as to suppress tumor growth); reducing the number of cancer cells; inhibiting, retarding or slowing to some extent and preferably stopping cancer cell infiltration into peripheral organs; inhibiting (slowing to some extent and preferably stopping) tumor metastasis; inhibiting tumor growth; preventing or delaying occurrence and/or recurrence of tumor; and/or relieving to some extent one or more of the symptoms associated with the cancer. In some embodiments, beneficial or desired results include preventing or delaying occurrence and/or recurrence, such as of unwanted cell proliferation (idiopathic pulmonary fibrosis (IPF)). [53] As used herein, "delaying development of a disease" means to defer, hinder, slow, retard, stabilize, and/or postpone development of the disease (such as cancer, pulmonary arterial hypertension (PAH) and idiopathic pulmonary fibrosis (IPF)). This delay can be of varying lengths of time, depending on the history of the disease and/or individual being treated. As is evident to one skilled in the art, a sufficient or significant delay can, in effect, encompass prevention, in that the individual does not develop the disease. For example, a late stage cancer, such as development of metastasis, may be delayed. [54] As used herein, an "effective dosage" or "effective amount" of compound or salt thereof or pharmaceutical composition is an amount sufficient to effect beneficial or desired results. For prophylactic use, beneficial or desired results include results such as eliminating or reducing the risk, lessening the severity of, or delaying the onset of the disease, including biochemical, histological and/or behavioral symptoms of the disease, its complications and intermediate pathological phenotypes presenting during development of the disease. For therapeutic use, beneficial or desired results include ameliorating, palliating, lessening, delaying or decreasing one or more symptoms resulting from the disease, increasing the quality of life of those suffering from the disease, decreasing the dose of other medications required to treat the disease, enhancing effect of another medication such as via targeting, delaying the progression of the disease, and/or prolonging survival. In reference to cancers or other unwanted cell proliferation, an effective amount comprises an amount sufficient to cause a tumor to shrink and/or to decrease the growth rate of the tumor (such as to suppress tumor growth) or to prevent or delay other unwanted cell proliferation (idiopathic pulmonary fibrosis (IPF)). In reference to pulmonary arterial hypertension (PAH), an effective amount comprises an amount sufficient to prevent or delay the development of pulmonary arterial hypertension (PAH)). In some embodiments, an effective amount is an amount sufficient to delay development. In some embodiments, an effective amount is an amount sufficient to prevent or delay occurrence and/or recurrence. An effective amount can be administered in one or more administrations, in the case of cancer, the effective amount of the drug or composition may: (i) reduce the number of cancer cells; (ii) reduce tumor size; (iii) inhibit, retard, slow to some extent and preferably stop cancer cell infiltration into peripheral organs; (iv) inhibit (i.e., slow to some extent and preferably stop) tumor metastasis; (v) inhibit tumor growth; (vi) prevent or delay occurrence and/or recurrence of tumor; and/or (vii) relieve to some extent one or more of the symptoms associated with the cancer. An effective dosage can be administered in one or more administrations. For purposes of this disclosure, an effective dosage of compound or a salt thereof, or pharmaceutical composition is an amount sufficient to accomplish prophylactic or therapeutic treatment either directly or indirectly. It is intended and understood that an effective dosage of a compound or salt thereof, or pharmaceutical composition may or may not be achieved in conjunction with another drug, compound, or pharmaceutical composition. Thus, an "effective dosage" may be considered in the context of administering one or more therapeutic agents, and a single agent may be considered to be given in an effective amount if, in conjunction with one or more other agents, a desirable result may be or is achieved. [55] As used herein, the term "individual" is a mammal, including humans. An individual includes, but is not limited to, human, bovine, horse, feline, canine, rodent, or primate. In some embodiments, the individual is human. The individual (such as a human) may have advanced disease or lesser extent of disease, such as low tumor burden. In some embodiments, the individual is at an early stage of a proliferative disease (such as cancer or idiopathic pulmonary fibrosis (IPF)). In some embodiments, the individual is at an advanced stage of a proliferative disease (such as an advanced cancer). [56] Reference to "about" a value or parameter herein includes (and describes) embodiments that are directed to that value or parameter per se. For example, description referring to "about X" includes description of "X". [57] It is understood that aspects and variations described herein also include "consisting" and/or "consisting essentially of aspects and variations. Compounds [58] The present invention provides a compound of Formula (J): L/Q Xn ^CN " (Rx)o-2 N N X, H formula (J), wherein, Xi and X2 are independently N or CRX; provided that at least one of Xi andX2isN; each Rxis independently hydrogen, Ci-C6 alkyl, C3-C6 cycloalkyl, 3- to 6-membered heterocyclyl, -CN, halogen, Ci-C6alkoxy, Ci-C6haloalkoxy, Ci-C6haloalkyl, -OR7, -NR8R9, -C(0)R7, -NR7C(0)R8, -C(0)0R7 or -C(0)NR8R9, each of which is optionally substituted by oxo, halogen, CN, -OR10 or -NRnR12; LisNHorO; QisCorD; C is 7- to 12-membered monocyclic or bicyclic heterocyclyl, C3-C10 monocyclic or bicyclic cycloalkyl or -(C1-C3 alkylene)Cy-Cio cycloalkyl, wherein each of C is optionally substituted by one or more R4; D is -(C1-C3 alkylene)3- to 6-membered heterocyclyl optionally substituted by one or more R4; A is R1 or Rla; R is independently 5-membered heteroaryl, 3- to 6-membered heterocyclyl or -C(0)NR2R3, wherein 5-membered heteroaryl and 3- to 6-membered heterocyclyl optionally substituted by R5; Rla is independently -C(0)NR2R3, Ci-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C6 cycloalkyl, 3- to 6-membered heterocyclyl, C6 aryl, 5- to 10- membered heteroaryl, -CN, halogen, Ci-C6alkoxy, Ci-C6haloalkoxy, Ci- Cehaloalkyl, -OR13, -SR13, -S(0)2R13, -S(0)2NR14R15, -NR13S(0)2R14, -NR14R15, -C(0)R13, -NR13C(0)R14, -NR13C(0)NR14R15, -C(0)OR13, -C(0)0NR14R15, -(Ci- C3 alkylene)OR13, -(C1-C3 alkylene)SR13, -(C1-C3 alkylene)S(0)2R13, -(Ci- C3 alkylene)S(0)2NR14R15, -(C1-C3 alkylene)NR13S(0)2R14, -(Ci- C3 alkylene)NR14R15, -(CrC3 alkylene)C(0)R13, -(Ci- C3 alkylene)NR13C(0)R14, -(CrC3 alkylene)NR13C(0)NR14R15, -(Ci- C3 alkylene)C(0)OR13, -(C1-C3 alkylene)C(0)ONR14R15, -(C1-C3 alkylene)(C3-C8 cycloalkyl) or -(Ci-C3 alkylene)(3-10-membered heterocyclyl); wherein each of Rla is optionally substituted by R5; R2andR3 are independently hydrogen, -CD3, Ci-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C6 cycloalkyl, 3- to 6-membered heterocyclyl, C6 aryl, 5- to 6- membered heteroaryl, , Ci-C6haloalkyl, -C(0)R13, -(C1-C3 alkylene)OR13, -(Ci- C3 alkylene)SR13, -(C1-C3 alkylene)S(0)2R13, -(Ci- C3 alkylene)S(0)2NR14R15, -(CrC3 alkylene)NR13S(0)2R14, -(Ci- C3 alkylene)NR14R15, -(CrC3 alkylene)C(0)R13, -(Ci- C3 alkylene)NR13C(0)R14, -(C1-C3 alkylene)NR13C(0)NR14R15, -(Ci- C3 alkylene)C(0)OR13, -(C1-C3 alkylene)C(0)ONR14R15, -(C1-C3 alkylene)(C3-C8 cycloalkyl), -(C1-C3 alkylene)(3-10-membered heterocyclyl), -(C1-C3 alkylene)C6 aryl or -(C1-C3 alkylene) 5- to 6-membered heteroaryl, wherein each of R2 and R3 are independently optionally substituted by R ; or R andR are taken together with the atom to which they attached to form a 3- to 6- membered heterocyclyl optionally substituted by R5; R4is oxo, Ci-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, -CN, halogen, Ci- C6alkoxy, Ci-C6haloalkoxy, -OR16, -SR16, -S(0)2R16 , -S(0)2NR17R18, -NR16S(0)2R17, -NR17R18, -C(0)R16, -NR16C(0)R17, -C(0)0R16, wherein each of R4 is optionally substituted by oxo, -OH, halogen or -NH2; R5 is oxo, Ci-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, -CN, halogen, Ci-C6haloalkyl, Ci-C6alkoxy, Ci-C6haloalkoxy, -OR16, -SR16, -S(0)2R16 , -S(0)2NR17R18, -NR16S(0)2R17, -NR17R18, -C(0)R16, -NR16C(0)R17, -C(0)0R16, C3-C6 cycloalkyl, C6 aryl, 5- to 6-membered heteroaryl, 3- to 6-membered heterocyclyl, wherein each of R5 is optionally substituted by oxo, -OH, halogen or -NH2; each R7, R8andR9is independently hydrogen or Ci-C6 alkyl optionally substituted by oxo, -OH, halogen or -NH2; each R , R and R is independently hydrogen, C1-C6 alkyl or C3-C8 cycloalkyl; or RnandR12 are taken together with the atom to which they attached to form a 3- to 6- membered heterocyclyl; each R , R and R is independently hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C6 cycloalkyl, 3- to 6-membered heterocyclyl, C6 aryl, 5- to 6-membered heteroaryl, -(C1-C3 alkylene)C3-C6 cycloalkyl, -(C1-C3 alkylene)3- to 6-membered heterocyclyl, or -(Ci-C3 alkylene)5- to 6-membered heteroaryl, wherein each of R , R and R is independently optionally substituted by oxo, C2-C6 alkenyl, C2-C6 alkynyl, -CN, halogen, Ci-C6alkoxy, Ci-C6haloalkoxy, -OR16, -SR16, -S(0)2R16 , -S(0)2NR17R18, -NR16S(0)2R17, -NR17R18, -C(0)R16, -NR16C(0)R17, -C(0)0R16 or Ci-C6 alkyl optionally substituted by oxo, -OH, halogen or -NH2; or R andR1" are taken together with the atom to which they attached to form a 3- to 6- membered heterocyclyl optionally substituted by oxo, OH or halogen, or Ci-C6 alkyl optionally substituted by oxo, -OH, halogen or -NH2; each R16, R17 and R18 is independently hydrogen, C2-C6 alkenyl, C2-C6 alkynyl, C6 aryl, 5- to 6-membered heteroaryl, 3- to 6-membered heterocyclyl, C3-C6 cycloalkyl or Ci-C6 alkyl optionally substituted by oxo, -OH, halogen or -NH2; and or R17andR18 are taken together with the atom to which they attached to form a 3- to 6- membered heterocyclyl optionally substituted by oxo, -OH, halogen or -NH2, or C1-C6 alkyl optionally substituted by oxo, -OH, halogen or - NH2; provided that: [59] when Q is C then L is -O- or -NH- and A is Rla; [60] when Q is D then L is -NH- and A is R1; [61] when Q is D, L is -NH- and A is R1 then: HN' (i) when D is ? • ancj Xi and X2 both are N; then R1 is other than H2N / H f H f F H L11C4.11 , , , , , ^ ^ -y* v* en** cM Cr«X/ b> N-N N-N 5 5 5 ^ / ' Jl <7 1 P H /, H ^and /; (ii) the compound is not selected from: 6-(5-cyanopyrazin-2-ylamino)-4-(piperidin-4-ylmethylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-N-methyl-4-((l-methylpiperidin-4-yl)methylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-4-((tetrahydro-2H-pyran-4-yl)methylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-N-methyl-4-((tetrahydro-2H-pyran-4-yl)methylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-N,N-dimethyl-4-(piperidin-4-ylmethylamino)pyridazine-3-carboxamide; 6-(6-cyanopyridin-3-ylamino)-N-methyl-4-(morpholin-2-ylmethylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-N-(3,3-difluorocyclobutyl)-4-(piperidin-4-ylmethylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-4-(piperidin-4-ylmethylamino)-N-(trifluoromethyl)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-4-(piperidin-4-ylmethylamino)-N-(2,2,2-trifluoroethyl)pyri dazine -3 -carb oxami de; 6-(5-cyanopyrazin-2-ylamino)-N-methyl-4-((4-methylmorpholin-2-yl)methylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-N,N-dimethyl-4-((4-methylmorpholin-2-yl)methylamino)pyridazine-3-carboxamide; 6-(5-cyanopyridin-2-ylamino)-N-methyl-4-(morpholin-2-ylmethylamino)pyri dazine-3-carboxamide; (R)-6-(6-cyanopyridin-3-ylamino)-N-methyl-4-(morpholin-2-ylmethylamino)pyridazine-3-carboxamide; (S)-6-(6-cyanopyridin-3-ylamino)-N-m ethyl -4-(morpholin-2-ylmethylamino)pyridazine-3-carboxamide; (R)-6-(5-cyanopyridin-2-ylamino)-N-methyl-4-(morpholin-2-ylmethylamino)pyridazine-3-carboxamide; (S)-6-(5-cyanopyridin-2-ylamino)-N-m ethyl -4-(morpholin-2-ylmethylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-N-methyl-4-(piperidin-3-ylmethylamino)pyridazine-3-carboxamide; (R)-6-(5-cyanopyrazin-2-ylamino)-N-m ethyl-4-(piperidin-3-ylmethylamino)pyridazine-3-carboxamide; (S)-6-(5-cyanopyrazin-2-ylamino)-N-methyl-4-(piperidin-3-ylmethylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-4-((2,6-dimethylpiperidin-3-yl)methylamino)-N-methylpyridazine-3 -carboxamide; 6-(5-cyanopyrazin-2-ylamino)-N-methyl-4-(pyrrolidin-3-ylmethylamino)pyridazine-3-carboxamide; 5-(6-(l-methyl-lH-pyrazol-3-yl)-5-(piperidin-4-ylmethylamino)pyridazin-3-ylamino)pyrazine-2-carbonitrile; 5-(6-(lH-imidazol-2-yl)-5-(piperidin-4-ylmethylamino)pyridazin-3-ylamino)pyrazine-2-carbonitrile; 5-(6-(lH-imidazol-2-yl)-5-((l-methylpiperidin-4-yl)methylamino)pyridazin-3-ylamino)pyrazine-2-carbonitrile; or 5-(6-(azetidin-l-yl)-5-(piperidin-4-ylmethylamino)pyridazin-3-ylamino)pyrazine-2-carbonitrile. [62] In some embodiments, a compound of formula (J) is a compound of formula (I): XL ^CN —(Rx)o-2 N N X2 H formula (I), wherein, Xi and X2 are independently N or CRX; provided that at least one of Xi andX2isN; each Rxis independently hydrogen, Ci-C6 alkyl, C3-C6 cycloalkyl, 3- to 6-membered heterocyclyl, -CN, halogen, Ci-C6alkoxy, Ci-C6haloalkoxy, Ci-C6haloalkyl, -OR7, -NR8R9, -C(0)R7, -NR7C(0)R8, -C(0)0R7 or -C(0)NR8R9, each of which is optionally substituted by oxo, halogen, CN, -ORlu or -NR^R ; D is -(C1-C3 alkylene)3- to 6-membered heterocyclyl, optionally substituted by R4; R1 is independently 5-membered heteroaryl, 3- to 6-membered heterocyclyl or -C(0)NR R , wherein 5-membered heteroaryl and 3- to 6-membered heterocyclyl optionally substituted by R ; R2andR3 are independently hydrogen, -CD3, Ci-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C6 cycloalkyl, 3- to 6-membered heterocyclyl, C6 aryl, 5- to 6- membered heteroaryl, , Ci-C6haloalkyl, -C(0)R13, -(C1-C3 alkylene)OR13, -(d- C3 alkylene)SR13, -(C1-C3 alkylene)S(0)2R13, -(Ci- C3 alkylene)S(0)2NR14R15, -(CrC3 alkylene)NR13S(0)2R14, -(Ci- C3 alkylene)NR14R15, -(CrC3 alkylene)C(0)R13, -(Ci- C3 alkylene)NR13C(0)R14, -(CrC3 alkylene)NR13C(0)NR14R15, -(Ci- C3 alkylene)C(0)OR13, -(C1-C3 alkylene)C(0)ONR14R15, -(C1-C3 alkylene)(C3-C8 cycloalkyl) or -(Ci-C3 alkylene)(3-10-membered heterocyclyl), -(Ci-C3 alkylene)C6 aryl or -(C1-C3 alkylene) 5- to 6-membered heteroaryl, wherein each of R2 and R3 are independently optionally substituted by R5; or R2 andR3 are taken together with the atom to which they attached to form a 3- to 6- membered heterocyclyl optionally substituted by R ; R4is oxo, Ci-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, -CN, halogen, Ci- C6alkoxy, Ci-C6haloalkoxy, -OR16, -SR16, -S(0)2R16 , -S(0)2NR17R18, -NR16S(0)2R17, -NR17R18, -C(0)R16, -NR16C(0)R17, -C(0)OR16, wherein each of R is optionally substituted by oxo, -OH, halogen or -NH2; R is oxo, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, -CN, halogen, Ci- C6alkoxy, Ci-C6haloalkoxy, -OR16, -SR16, -S(0)2R16 , -S(0)2NR17R18, -NR16S(0)2R17, -NR17R18, -C(0)R16, -NR16C(0)R17, -C(0)OR16, C3-C6 cycloalkyl, C6 aryl, 5- to 6-membered heteroaryl, 3- to 6-membered heterocyclyl, wherein each of R is optionally substituted by oxo, -OH, halogen or -NH2; each R7, R8andR9is independently hydrogen or Ci-C6 alkyl optionally substituted by oxo, -OH, halogen or -NH2; each R , R and R is independently hydrogen, C1-C6 alkyl or C3-C8 cycloalkyl; or RnandR12 are taken together with the atom to which they attached to form a 3- to 6- membered heterocyclyl; each R13, R14 and R15 is independently hydrogen, Ci-C6 alkyl, Ci-C6 haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C6 cycloalkyl, 3- to 6-membered heterocyclyl, C6 aryl, 5- to 6-membered heteroaryl, -(C1-C3 alkylene)C3-C6 cycloalkyl, -(C1-C3 alkylene)3- to 6-membered heterocyclyl, or -(Ci-C3 alkylene)5- to 6-membered heteroaryl, wherein each of R13, R14 and R15 is independently optionally substituted by oxo, C2-C6 alkenyl, C2-C6 alkynyl, -CN, halogen, Ci-C6alkoxy, Ci-C6haloalkoxy, -OR16, -SR16, -S(0)2R16 , -S(0)2NR17R18, -NR16S(0)2R17, -NR17R18, -C(0)R16, -NR16C(0)R17, -C(0)OR16 or Ci-C6 alkyl optionally substituted by oxo, -OH, halogen or -NH2; or R14andR15 are taken together with the atom to which they attached to form a 3- to 6- membered heterocyclyl optionally substituted by oxo, OH or halogen, or Ci-C6 alkyl optionally substituted by oxo, -OH, halogen or -NH2; each R16, R17 and R18 is independently hydrogen, C2-C6 alkenyl, C2-C6 alkynyl, C6 aryl, 5- to 6-membered heteroaryl, 3- to 6-membered heterocyclyl, C3-C6 cycloalkyl or C1-C6 alkyl optionally substituted by oxo, -OH, halogen or -NH2; and or R17andR18 are taken together with the atom to which they attached to form a 3- to 6- membered heterocyclyl optionally substituted by oxo, -OH, halogen or -NH2, or C1-C6 alkyl optionally substituted by oxo, -OH, halogen or - NH2; provided that: HN' (i) when D is ^ • ancj Xi and X2both are N; then R is other H2N Y H f H * I F H than O N H ■^j I II ^^^^N^v F p O O H I O H # W * S H ^ O ° A ftV* Cv ^7 ?f (1 p H f, H r and ? ; (ii) the compound is not selected from: 6-(5-cyanopyrazin-2-ylamino)-4-(piperidin-4-ylmethylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-N-methyl-4-((l-methylpiperidin-4- yl)methylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-4-((tetrahydro-2H-pyran-4-yl)methylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-N-methyl-4-((tetrahydro-2H-pyran-4-yl)methylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-N,N-dimethyl-4-(piperidin-4-ylmethylamino)pyridazine-3-carboxamide; 6-(6-cyanopyridin-3-ylamino)-N-methyl-4-(morpholin-2-ylmethylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-N-(3,3-difluorocyclobutyl)-4-(piperidin-4-ylmethylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-4-(piperidin-4-ylmethylamino)-N-(trifluoromethyl)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-4-(piperidin-4-ylmethylamino)-N-(2,2,2-trifluoroethyl)pyri dazine -3 -carb oxami de; 6-(5-cyanopyrazin-2-ylamino)-N-methyl-4-((4-methylmorpholin-2-yl)methylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-N,N-dimethyl-4-((4-methylmorpholin-2-yl)methylamino)pyridazine-3-carboxamide; 6-(5-cyanopyridin-2-ylamino)-N-methyl-4-(morpholin-2-ylmethylamino)pyri dazine-3-carboxamide; (R)-6-(6-cyanopyridin-3-ylamino)-N-methyl-4-(morpholin-2-ylmethylamino)pyridazine-3-carboxamide; (S)-6-(6-cyanopyridin-3 -ylamino)-N-m ethyl -4-(morpholin-2- ylmethylamino)pyridazine-3-carboxamide; (R)-6-(5-cyanopyridin-2-ylamino)-N-methyl-4-(morpholin-2-ylmethylamino)pyridazine-3-carboxamide; (S)-6-(5-cyanopyridin-2-ylamino)-N-m ethyl-4-(morpholin-2-ylmethylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-N-methyl-4-(piperidin-3-ylmethylamino)pyridazine-3-carboxamide; (R)-6-(5-cyanopyrazin-2-ylamino)-N-m ethyl-4-(piperidin-3-ylmethylamino)pyridazine-3-carboxamide; (S)-6-(5-cyanopyrazin-2-ylamino)-N-methyl-4-(piperidin-3-ylmethylamino)pyridazine-3-carboxamide; 6-(5-cyanopyrazin-2-ylamino)-4-((2,6-dimethylpiperidin-3-yl)methylamino)-N-methylpyridazine-3 -carboxamide; 6-(5-cyanopyrazin-2-ylamino)-N-methyl-4-(pyrrolidin-3-ylmethylamino)pyridazine-3-carboxamide; 5-(6-(l-methyl-lH-pyrazol-3-yl)-5-(piperidin-4-ylmethylamino)pyridazin-3-ylamino)pyrazine-2-carbonitrile; 5-(6-(lH-imidazol-2-yl)-5-(piperidin-4-ylmethylamino)pyridazin-3-ylamino)pyrazine-2-carbonitrile; 5-(6-(lH-imidazol-2-yl)-5-((l-methylpiperidin-4-yl)methylamino)pyridazin-3-ylamino)pyrazine-2-carbonitrile; or 5-(6-(azetidin-l-yl)-5-(piperidin-4-ylmethylamino)pyridazin-3-ylamino)pyrazine-2-carbonitrile. [63] In some embodiments of a compound of formula (J), Xi and X2 are independently N or CRX; provided that at least one of Xi and X2 is N. In some embodiments of a compound of formula (J), Xi is N and X2 is CRX. In some embodiments of a compound of formula (J), Xi is CRX and X2 is N. In some embodiments Xi and X2 both are N. [64] In some embodiments, Rxis independently selected from hydrogen, Ci-C6 alkyl, C3-C6 cycloalkyl, 3- to 6-membered heterocyclyl, -CN, halogen, Ci- C6alkoxy, Ci-C6haloalkoxy, Ci-C6haloalkyl, -OR7, NR8R9, -C(0)R7, -NR7C(0)R8, -C(0)OR7 or -C(0)NR8R9, each of which is optionally substituted by oxo, halogen, CN, -OR10 or -NRUR12. In some embodiments, Rxis hydrogen. [65] In some embodiments of a compound of formula (J), L is NH. In some embodiments of a compound of formula (J), L is O. [66] In some embodiments of a compound of formula (J), C is 7- to 12- membered monocyclic or bicyclic heterocyclyl optionally substituted by one or more R . In some embodiments of a compound of formula (J), 7- to 12-membered heterocyclyl is monocyclic heterocyclyl optionally substituted by one or more R4. In some embodiments of a compound of formula (J), 7- to 12-membered heterocyclyl is bicyclic heterocyclyl optionally substituted by one or more R4, which is fused, spiro or bridge bicyclic heterocyclyl. In some embodiments of a compound of formula (J), C is C3-C10 monocyclic or bicyclic cycloalkyl, which is optionally substituted by one or more R4. In some embodiments of a compound of formula (J), C3-C10 cycloalkyl ring is monocyclic cycloalkyl optionally substituted by one or more R . In some embodiments of a compound of formula (J), C3-C10 cycloalkyl ring is bicyclic cycloalkyl optionally substituted by one or more R . In some embodiments of a compound of formula (J), C is azepanyl, decahydroquinoline, decahydroisoquinoline, octahydro-lH-indole, octahydrocyclopenta[b]pyrrole, octahydro-lH-cyclopenta[b]pyridine, octahydro-lH-cyclopenta[b]pyridine, octahydro-lH-cyclopenta[b]pyridine, octahydro-lH- cyclopenta[c]pyridine, octahydro-lH-cyclopenta[c]pyridine, octahydrocyclopenta[b]pyrrole, octahydrocyclopenta[c]pyrrole, 2- azabicyclo[3.2.0]heptane, 2-azabicyclo[4.2.0]octane, 3-azabicyclo[4.2.0]octane, 2-azaspiro[3.3]heptane, l-azaspiro[3.3]heptane, 5-azaspiro[3.4]octane, 6-azaspiro[3.4]octane, 5-azaspiro[3.5]nonane, 6-azaspiro[3.5]nonane, 7-azaspiro[3.5]nonane, 2-azaspiro[3.4]octane, l-azaspiro[3.4]octane, 1-azaspiro[4.4]nonane, 2-azaspiro[4.4]nonane, 6-azaspiro[4.5]decane, 7-azaspiro[4.5]decane, 8-azaspiro[4.5]decane, 2-azaspiro[3.5]nonane, 1-azaspiro[3.5]nonane, l-azaspiro[4.5]decane, 2-azaspiro[4.5]decane, 1-azaspiro[5.5]undecane, 2-azaspiro[5.5]undecane, 3-azaspiro[5.5]undecane, cyclopropyl, cyclobutyl, cyclopentyl cyclohexyl, bicyclo[l.l.l]pentyl, decahydronaphthalene, octahydro-lH-indene or octahydropentalene, wherein each of C is optionally substituted by one or more R4. [67] In some embodiments of a compound of formula (J), C is -(Ci-C3 alkylene)C7-Cio cycloalkyl optionally substituted by one or more R , wherein cycloalkyl ring is monocylic or bicyclic. In one variation, C1-C3 alkylene as disclosed herein (in formula (J)) is substituted by one or more R4 or unsubstituted. In other variation, C1-C3 alkylene is a linear alkylene such as -CH2-. In another variation, C1-C3 alkylene is a branched alkylene, such as -CH(CH3)- and -C(CH3)2-. In some embodiments of a compound of formula (J), C is -CH2-(bicyclo[3.1.1]heptane)and-CH2-((lR,5S)-bicyclo[3.2.1]octane). [68] In some embodiments of a compound of formula (J), D is -(Ci-C3 alkylene)3- to 6-membered heterocyclyl optionally substituted by one or more R . In one variation, C1-C3 alkylene as disclosed herein (in formula (J)) is substituted by one or more R4 or unsubstituted. In other variation, C1-C3 alkylene is a linear alkylene such as -CH2-, -CH2—CH2-. In another variation, C1-C3 alkylene is a branched alkylene, such as -CH(CH3)- and -C(CH3)2-. [69] In some embodiments of a compound of formula (J), D is -CH2-(3- to 6-membered heterocyclyl) optionally substituted by one or more R . In some embodiments of a compound of formula (J), D is -CH2-CH2-(3- to 6-membered heterocyclyl) optionally substituted by one or more R . In some embodiments of a compound of formula (J), D is selected from -CH(CH3)-(3- to 6-membered heterocyclyl) or -C(CH3)2-(3- to 6-membered heterocyclyl), each of which is optionally substituted by one or more R4. In some embodiments of a compound of formula (J), D is -CH2-(4-membered heterocyclyl) optionally substituted by one or more R . In some embodiments of a compound of formula (J), D is -CH2-(5-membered heterocyclyl) optionally substituted by one or more R4. In some embodiments of a compound of formula (J), D is -CH2-(6-membered heterocyclyl) optionally substituted by one or more R4. [70] In some embodiments of a compound of formula (J), R is oxo, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, -CN, halogen, Ci-Cealkoxy, Ci-C6haloalkoxy, -OR16, -SR16, -S(0)2R16 , -S(0)2NR17R18, -NR16S(0)2R17, -NR17R18, -C(0)R16, -NR16C(0)R17, -C(0)OR16, wherein each of R4 is optionally substituted by oxo, -OH, halogen or -NH2. In some embodiments of a compound of formula (J), R is C1-C6 alkyl. In some embodiments of a compound of formula (J), R4 is methyl. In some embodiments of a compound of formula (J), R4 is -NH2, -F, -OH, -NH-CH3, and -N-(CH3)2. In some embodiments of a compound of formula (J), R4 is -NH2. In some embodiments of a compound of formula (J), R4 is -F. In some embodiments of a compound of formula (J), R is -OH. In some embodiments of a compound of formula (J), R4 is -NHCH3. In some embodiments of a compound of formula (J), R4 is -N(CH3)2. [71] In some embodiments of a compound of formula (J), D is selected from the group of but not limited to ? , * , * , ^ ^ n. NH X NH H N X X H .N. HN^ HN F X X ^ , ^ or ^ X^ 1 denote attachment points to rest of the molecule wherein the wavy lines HN^| [72] In some embodiments of a compound of formula (J), D is ^ . In ^ 'N some embodiments of a compound of formula (J), D is ^ . In some H .N. embodiments of a compound of formula (J), D is ^ . In some embodiments NH of a compound of formula (J), D is * . In some embodiments of a compound .N, of formula (J), D is ^- . In some embodiments of a compound of formula (J), NH D is ^- .In some embodiments of a compound of formula (J), D is In some embodiments of a compound of formula (J), D is * H N NH In some embodiments of a compound of formula (J), D is ^ .In some NH D is ^ In some embodiments of a compound of formula (J), embodiments of a compound of formula (J), D is ^ In some embodiments of a compound of formula (J), HN Dis ^ H .N, In some embodiments of a compound of formula (J), D is Y .In some embodiments of a HN- Dis ^ compound of formula (J), [73] In some embodiments of a compound of formula (J), C is selected from the NH2 (o ^NH2 .NH, in V X jr group of but not limited to T- XT™ V OH HN NH T ^ V H -N. H NH HN I ) HX3 wherein the wavy lines denote attachment points to rest of the molecule. [74] In some embodiments of a compound of formula (J), C »* iVvNH2 NH, .In some embodiments of a compound of formula (J), C »v In some embodiments of a compound of formula (J), C NH, In some OH embodiments of a compound of formula (J), C is ^- .In some NH2 embodiments of a compound of formula (J), C is ^ .In some ,NH2 In some embodiments of a compound of formula (J), C is ^- embodiments of a compound of formula (J), C . X is ^~ NH, In some NH, is embodiments of a compound of formula (J), C is ^ .In some NH2 embodiments of a compound of formula (J), C is ^- N—' . In some NH2 embodiments of a compound of formula (J), C is " ^~-~~J . In some embodiments of a compound of formula (J), C lsv In some embodiments of a compound of formula (J), C is ^~ N, In some embodiments of a compound of formula (J), C Xf is\' N. In some NH In some embodiments of a compound of formula (J), C is ^ NH2 embodiments of a compound of formula (J), C is ^- ~ .In some embodiments H2N. In some embodiments of a is ^ of a compound of formula (J), C i NH2 compound of formula (J), C is ^- .In some embodiments of a compound of iA formula (J), C OH NH2 In some embodiments of a compound of formula (J), C is ^ .In some embodiments of a compound of formula (J), C is OH OH In some embodiments of a compound of formula (J), C is ^- In some embodiments of a compound of formula (J), C A OH In some OH embodiments of a compound of formula (J), C »v In some embodiments of a compound of formula (J), C OH JX isV In some embodiments of a compound of formula (J), C is In some embodiments of a compound of formula (J), C compound of formula (J), C In some embodiments of a [75] In some embodiments of a compound of formula (J), R is selected from 5-membered heteroaryl, 3- to 6-membered heterocyclyl or -C(0)NR R , wherein 5-membered heteroaryl and 3- to 6-membered heterocyclyl optionally substituted by R5. [76] In some embodiments of a compound of formula (J), R ais -C(0)NR R . la- in some embodiments of a compound of formula (J), R is C\-Ce alkyl optionally la- substituted by R . In some embodiments of a compound of formula (J), R is C2-C6 alkenyl optionally substituted by R5. In some embodiments of a compound of formula (J), Ra is C2-C6 alkynyl optionally substituted by R . In some embodiments of a compound of formula (J), R a is C3-C6 cycloalkyl optionally substituted by R5. In some embodiments of a compound of formula (J), Rlais 3- to 6-membered heterocyclyl optionally substituted by R5. In some embodiments of a compound of formula (J), Rla is C6 aryl optionally substituted by R5. In some embodiments of a compound of formula (J), R ais 5- to 10-membered heteroaryl optionally substituted by R5. In some embodiments of a compound of formula (J), Rlais-CN. In some embodiments of a compound of formula (J), Rlais halogen. In some embodiments of a compound of formula (J), R a is C1-C6 alkoxy. In some embodiments of a compound of formula (J), R a is Ci-Cehaloalkoxy. In some embodiments of a compound of formula (J), Rla is Ci-C6haloalkyl. In some embodiments of a compound of formula (J), Rlais -OR13. In some embodiments of a compound of formula (J), Rlais -SR13. In some embodiments of a compound of formula (J), R is -S(0)2R . In some embodiments of a compound of formula (J), Rlais -S(0)2NR14R15. In some embodiments of a compound of formula (J), Rla is -NR13S(0)2R14. In some embodiments of a compound of formula (J), Rla is -NR14R15. In some embodiments of a compound of formula (J), Rlais -C(0)R13. In some embodiments of a compound of formula (J), R ais -NR C(0)R . In some embodiments of a compound of formula (J), Rlais -NR13C(0)NR14R15. In some embodiments of a compound of formula (J), Rla is -C(0)OR13. In some embodiments of a compound of formula (J), Rla is -C(0)ONR14R15. In some embodiments of a compound of formula (J), R ais -(C1-C3 alkylene)OR , In some embodiments of a compound of formula (J), R ais -(C1-C3 alkylene)SR . In some embodiments of a compound of formula (J), Rla is -(Ci-C3 alkylene)S(0)2R13, -(CrC3 alkylene)S(0)2NR14R15. In some embodiments of a compound of formula (J), Rla is -(CrC3 alkylene)NR13S(0)2R14. In some embodiments of a compound of formula (J), Rlais -(C1-C3 alkylene)NR14R15. In some embodiments of a compound of formula (J), Rla is -(Ci-C3 alkylene)C(0)R13. In some embodiments of a compound of formula (J), R a is -(C1-C3 alkylene)NR13C(0)R14. In some embodiments of a compound of formula (J), R is -(C1-C3 alkylene)NR1X(0)NR14R°. In some embodiments of a compound of formula (J), Rla is -(C1-C3 alkylene)C(0)OR13. In some embodiments of a compound of formula (J), Rla is -(Ci-C3 alkylene)C(0)ONR14R15. In some embodiments of a compound of formula (J), Rlais -(C1-C3 alkylene)(C3-C8 cycloalkyl). In some embodiments of a compound of formula (J), R ais -(C1-C3 alkylene)(3-10-membered heterocyclyl). [77] In some embodiments of a compound of formula (J), C1-C3 alkylene of Rla is substituted by R or unsubstituted. In some embodiments of a compound of formula (J), C1-C3 alkylene of R ais linear or branched. [78] In some embodiments of a compound of formula (J), R5 is oxo, Ci-C6 alkyl, halogen, Ci-C6alkoxy, Ci-C6haloalkoxy, -OR16, -SR16, -S(0)2R16 , -S(0)2NR17R18, -NR16S(0)2R17, -NR17R18, -C(0)R16, -NR16C(0)R17, -C(0)0R16, C3-C6 cycloalkyl, C6 aryl, 5- to 6-membered heteroaryl, 3- to 6-membered heterocyclyl, wherein each of R5 is optionally substituted by oxo, -OH, halogen or -NH2. In some embodiments of a compound of formula (J), R5is oxo, Ci-C6 alkyl or halogen, wherein each of R5 is optionally substituted by oxo, -OH, halogen or -NH2. In some embodiments of a compound of formula (J), R is oxo, methyl, ethyl, cyclopentyl, cyclopentyl substituted by -OH, di-floro substituted phenyl, -NH2, -OH, CI or F. [79] In some embodiments of a compound of formula (J), R1 is 5-membered heteroaryl optionally substituted by R . In some embodiments, R is selected from -ti -u 0 ^/ i^^^N^v . 1 ? U ° o fl fl^l fl ^ X, ^ ° H 5 9 o V /y ^ U^ QTH^ ^ ^ HA a^ aA/ oA/ cA '^V^^a^ 15. The compound of claim 1, wherein the compound is a compound of formula (IA): >1a .X^ XN ^ V —(RX)0-2 N N Xg H formula (IA), ,1a wherein Xi, X2, C, R , L and R are as defined in claim 1. 16. The compound of claim 1, wherein the compound is any of the compound of formula (IA-1 to IA-10): HN HN ,1a r^ IV ^CN (Rx)o-2 N N N H N N N H CN (Rx)o-2 (IA-1) (IA-2) R' 2 r>3 wherein Xi, X2, C, L, R , R and Rx are as defined in claim 1. 18. The compound of claim 1, wherein the compound is any of the compound of formula (IA-1 to IA-10): (Rx)o-2 (Rx)o-2 O HN' (IB-1) (IB-2) (Rx)o-: O HN' Ri 'N i R2 o o N N H N CN J> (Rx)o-2 N (IB-3) (IB-4) (Rx)o-: R^! o o R^! *N i R2 o o I N N H N..CN M (Rx)o-2 (IB-5) (IB-6) (Rx)o-: (IB-7) (IB-8) Nk ^CN -(Rx)o-: R2 N^ ^ ^ J> N N N H O HN NH2 (R4)o-4 N N Xf H formula (IV) |2 n3 wherein Xi, X2, D, R , R and R are as defined in claim 1. 24. The compound of claim 1, wherein the compound is any of the compound of formula (IV-a) to (IV-c): (Rx)o-2 JJ „N CN O HN' N N N H (IV-a) (IV-b) (Rx)o-2 O HN' (IV-c) wherein D, R2, R3 and Rx are as defined in claim 1. 25. The compound of claim 1, wherein the compound is a compound of formula (V): i (R )o-4 (Rx)o-: formula (V), wherein Xi, X2, R , R , R and Rx are as defined in claim 1. 26. The compound of claim 1, wherein the compound is any of the compound of formula of formula (V-a) to (V-f): HN' i (R )o-4 ,o HN^r-(R4)o-4 N R2 N. ^N' R2 N O HN' N ^N CN N N H O HN' N N CN -(Rx)o-: (V-a) (V-b) £-(R4) (Rx)o-: 'N N H (V-c) (V-d) HN' I (R )o-4 HN "(R4)o-4 O HN' N N II H N N CN (Rx)o-2 O HN' N ^N CN lT "(Rx)o-2 (V-e) (V-f) wherein R2, R3, R4 and Rx are as defined in claim 1. 27. The compound of claim 1, wherein the compound is a compound of formula (VI): (R4)CM X., .CN X ^(RX)°-2 R N^.<* N N Xo H formula (VI), wherein Xu X2, R2, R3, R4 and Rx are as defined in claim 1. 28. The compound of claim 1, wherein the compound is any of the compound of formula of formula (Vl-a) to (Vl-f): H N^CN —(R*)«K R? O HN Y R2 N.ki<^ N -(R4)CM CN il/nx N (Rx)o-: (Vl-a) (Vl-b) (R4)CM CN lT "(Rx)o-2 ^N CN lT -(Rx)o-2 (VI-c) (Vl-d) (RV» CN lT -(Rx)o-2 (VI-e) (VI-f) wherein R , R , R and Rx are as defined in claim 1. 29. The The compound of claim 1, wherein the compound is a compound of formula (VII): (R4)o-4 ^ f*xV_CN R2 N.N*LJV (RX)O-2 N N Xo H formula (VII), wherein Xu X2, R2, R3, R4 and Rx are as defined in claim 1. 30. The compound of claim 1, wherein the compound is any of the compound of formula of formula (VH-a) to (Vll-f): (Rx)o-2 (R4)> jl~(RX)o-2 N N N H (VH-a) (VH-b) N CN "Tj (Rx)o-2 N II H J HI^R* y N N N H (VH-c) (VH-d) H A ii (Rx)o-2 Rl O HN N HN 'N "(R4)CM CN -(Rx)o-2 'N' Rl N O HN N HN "(R4)o-4 (VH-e) (Vll-f) wherein R2, R3, R4 and Rx are as defined in claim 1. 31. The compound of claim 1, wherein the compound is a compound of formula (VIII): HN- O HN Rl ~N' R2 N^ -(R4)CM ^ CN L Tj (RX)o-2 N^V H formula (VIII), wherein Xu X2, R2, R3, R4 and Rx are as defined in claim 1. 32. The compound of claim 1, wherein the compound is any of the compound of formula of formula (VHI-a) to (Vlll-f): Ftf N R2 N 'N^N H Rl HN- O HN N -(R4)CM NvCN ~7j (Rx)o-2 HN- O HN' VN' "(R4)o- N CN -(Rx)o-: (VHI-a) (VHI-b) HN- O HN R N...A..A. N 'N R* "(R4)o-4 N CN R* HN- O HN N "(R4)CM X N CN —(Rx)o-2 J> N N H (VIII-c) (VHI-d) —(Rx)o-2 R^i HN- O HN' N -(R4)o-4 N CN (Rx)o-2 R* HN- O HN N N II H N1 -(R4)o-4 N^ ,CN (VHI-e) (VHI-f) wherein R2, R3, R4 and Rx are as defined in claim 1. 33. The compound of claim 1, wherein the compound is selected from Compound Nos. 1.1 to 1.354 in table-1 or a salt thereof. 34. The compound of any one of claims 1 to 33, being used for manufacture of a medicament for treatment of a disorder characterized by excessive level of Checkpoint kinase-1 (CHK-1).