Patent ID: 7671195

Claim:
A method of preparing a dibenzothiazepine compound of Formula I: in which each of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 , independently, represents a hydrogen atom, an alkyl group, an alkoxy group, an alkylcarbonyl group, an aryl group, an aryloxy group, or an arylcarbonyl group, each group being optionally substituted, which comprises steps of: reducing a 2-nitro-2′-carboxy-diphenylsulfide compound of Formula IV: in which each of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 is the same as defined above, in an aliphatic ester of an aliphatic alcohol having 1 to 6 carbon atoms and an aliphatic carboxylic acid having 1 to 6 carbon atoms to obtain the 2-amino-2′-carboxy-diphenylsulfide compound of Formula V: and subjecting the 2-amino-2′-carboxy-diphenylsulfide compound of Formula V to dehydration-condensation reaction in the presence of an acidic catalyst.