Process for the preparation of a 1,5-benzothiazepine derivative, or a salt thereof, of formula 1 ##STR1## where R1 represents H, an alkyl group or an alkoxy group and R.sub.2 represents H or a halogen, in which process a propanoic acid derivative of formula 2 ##STR2## where R.sub.1 and R.sub.2 are as defined above and R.sub.3 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, R.sub.2 is H and R.sub.1 is OCH.sub.3. 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.
制备1,5-
苯并噻吩啶衍
生物或其盐的过程,其
化学式为1,其中R1代表H、烷基或烷氧基,R.sub.2代表H或卤素,在该过程中,将
化学式2的
丙酸衍
生物进行分子内环化反应,其中R.sub.1和R.sub.2如上定义,R.sub.3代表H或烷基,在非卤代溶剂中,在存在
羧酸的情况下进行。最好是,R.sub.2为H,R.sub.1为OCH.sub.3。
三氯乙酸最好用作α-
氯化酸。通过环化得到的
苯并噻吩啶可以进行烷基化反应和/或酰化反应,以获得已知的药物产品,特别是
地尔硫卓。