Abstract: Provided is an industrially scalable process for the preparation of a benzazepine derivative, namely, 7-chloro-5-hydroxy-1-[2-methyl-4-(2-methyl benzoyl amino) benzoyl]-2,3,4,5-tetrahydro-1H-1-benzazepine (generically referred as Tolvaptan).

Abstract: A process for preparation of Methyl-(+)-(S)-alpha-(2-chlorophenyl)-6,7-dihydrothieno[3,2-c]pyridine-5(4H)-acetic acid methyl ester or salts thereof [clopidogrel or salts thereof of Formula (I)] having higher chiral purity and products thereof is provided. A process for purification of the compound prepared is also provided to enhance its efficacy by enhancing its optical rotation and chiral purity. In Formula (I), R is selected from a group comprising alkyl, alkoxy, hydroxy, amine etc., and R1 is selected from the group comprising C1-4 alkyl, C1-4 alkoxy, hydroxy, nitro & halogen. The particular salt of interest of the present invention is the hydrogen sulfate of compound of the Formula (I), wherein R and R1 are —OCH3 and chloro-group at position 2 respectively.

Abstract: A process for the preparation of 6-(2,3-dichlorophenyl)-1,2,4-triazine-3-5-diamine (lamotrigine) of the formula I: 2,3-Dichloronitrobenzene in C1-C6 aliphatic alkanol is hydrogenated at 55-90 psi gas pressure using metal catalyst at 27-35° C. 2,3-Dichloroaniline is diazotised and cyano-de-diazonised with metal cyanide at 65-80° C. 2,3-Dichlorobenzonitrile is hydrolysed and 2,3-dichlorobenzoic acid is chlorinated at 55-130° C. Cyano-de-halogenation of 2,3-dichlorobenzoyl chloride is carried out with a metal cyanide and alkali metal iodide by refluxing in an aprotic solvent under an inert atmosphere. 2,3-Dichlorobenzoyl cyanide is condensed with aminoguanidine bicarbonate in an organic solvent in acidic conditions using catalyst at 90-125° C. followed by insitu cyclisation of the Schiff's base by refluxing in an aliphatic alkanol with base. Crude lamotrigine is purified.