Patent ID: 7314930

Claim:
A process for preparing a dibenzothiazepine of the following formula (5): 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, an alkylcarbonyl, an aryl group, an aryloxy group, or an arylcarbonyl group, each group being optionally substituted, which comprises the steps of: reducing a 2-nitro-2′-carboxy-diphenylsulflde compound of the following formula (3): in which each of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 has the meaning as described above, in the presence of a hydrogen gas and a reducing catalyst selected from the group consisting of Raney-nickel, palladium/carbon, palladium/barium sulfate, a palladium compound and a platinum compound, to obtain a 2-amino-2′-carboxy-diphenylsulfide compound of the following formula (4): in which each of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 has the meaning as described above; and subjecting the obtained 2-amino-2′-carboxy-diphenyl sulfide compound to dehydration-condensation reaction.