Synthesis of 2-substituted-N-carboxymethyl-1,5-benzothiazepin-4-ones and -1,4-benzothiazin-3-ones and their evaluation as angiotensin converting enzyme inhibitors.

The title compounds 7a-d and 8a-e were synthesized and their in vitro inhibitory activity of angiotensin-converting enzyme (ACE) was examined. In general, these compounds possess poor ACE inhibitory activity. Among the benzothiazinone compounds, which are generally more active than the cyclohomologous compounds 7, 8b is the most effective (IC50 of 170 microM).