Patent ID: RE40033

Claim:
A method of preparing 2-methyl-4-(4-methyl-1-piperazinyl)-10H-thieno[2,3-b][1,5]-benzodiazepine comprising the following steps: A) preparing 2-amino-5-methylthiophene-3-carbonitrile by mixing sulfur, propional-dehyde propionaldehyde in dimethylformamide, then adding triethyl amine, then adding malononitrile; B) preparing 2-(2-nitroanilino)-5-methylthiophene-3-carbonitrile from the reaction product of step (A) by reaction with a slurry of sodium hydride dispersed in oil in tetrahydrofuran and 2-fluoro-nitrobenze 2 - fluoronitrobenzene ; C) preparing 4-amino-2-methyl-10H- thiono thieno [2,3-b][1,5]benzodiazepine hydrochloride from the reaction product of step (B) by reacting with a slurry of 2-(2-nitroanilino)-5-methyl-thiophene-3-carbonitrile in ethanol and a solution of anhydrous stannous chloride in hydrochloric acid; D) preparing 2-methyl-4-(4-methyl-1-piperazinyl)-10H-thieno[2,3-b][1,5]benzodiazepine by refluxing the reaction product of step (C) with a mixture of N-methylpiperazine, dimethylsulphoxide and toluene.