| 摘要 |
Process for the preparation of a 1,5-benzothiazepine derivative, or a salt thereof, of formula 1 <IMAGE> 1 where R1 represents H, an alkyl group or an alkoxy group and R2 represents H or a halogen, in which process a propanoic acid derivative of formula 2 <IMAGE> 2 where R1 and R2 are as defined above and R3 represents H or an alkyl group is subjected to an intramolecular cyclisation reaction in a non-halogenated solvent in the presence of a carboxylic acid. Preferably, R2 is H and R1 is OCH3. Trichloroacetic acid is preferably used as alpha -chlorinated acid. The benzothiazepine obtained on cyclisation can be subjected to an alkylation reaction and/or an acylation reaction to obtain known pharmaceutical products, in particular diltiazem.
|
