We Claim:
1. A process for preparing a highly pure and stable compound ! by condensation of compound II and compound III in dilute basic media in presence of PTC at low temperature
i. addition of PTC and Kl catalyst in to basic media.
ii. addition of compound II followed by compound III.
iii. maintaining the reaction mass at elevated temperature.
iv. extraction of compound I in to solvent, work up and isolation,
v. extraction of product compound I by further basilkation of mass and
in to solvent like Toluene to avoid process related impurities of compound II. vi. extraction of product compound I , to aqueous hydrochloride solution from
Toluene layer to avoid other process related impurities.. vii. extraction of Pure compound to solvent like dichloromethane ( MDC) from
aqueous acidic solution, viii. distillation ofdichloromethane completely under vacuum and isolation of
highly pure compound I by addition of solvent Ethyl acetate.
2. A process for preparing apure and stable compound I by condensation of compound 11 and compound 111 in mixture of dilute basic solution and solvent , in presence of PTC at low temperature
i. addition of PTC and Kl catalyst in to dilute basic media . mixture of aqueous sodium carbonate solution and miscible solvent or immiscible solvent ( as binary phase) or mixture of both miscible and immiscible solvents
ii. addition of compound II followed by compound III,
iii. maintaining the reaction mass at 60 to 65 C,
iv. separation of organic and aqueous layer after reaction completion.
v. extraction of product compound I by aqueous Hydrochloric, acid solution from
solvent.
vi. extraction of pure compound I from aqueous acidic solution by solvent like dichloromethane,
vii. removal of solvent completely under vacuum,
viii. isolation of highly pure compound I by addition of solvent ethyl acetate.
3. According 10 (he Claim I. llie basic media is sodium carbonate soktlion in water . specific 20% solution.
4. According to the Claim I. the PTC is selected from tern bulvl ammonium cliloridc or tetra butyl ammonium bromide.
5. According to the Claim 1, the elevated temperature is 50 to 70 C, specific 60 6o 65 C.
6. According to the Claim 2. the solvent is water soluble or water insoluble or ini.xture of both
7. According to the Claim 6: the solvent is selected from Toluene. MiBK jVIEK. acetone or mixture.
X. According to the Claim 1 and 2. the, highly pure compound 1 purity is about 99.9%. 9. According to the Claim I. the yield of isolated pure compound I is around 90%.