摘要:
A compound of the formula ##STR1## wherein R.sub.1 represents a hydrogen atom or a lower alkyl group, and R.sub.2 represents a hydrogen or halogen atom or a trifluoromethyl group,And its pharmaceutically acceptable salt. The compound is prepared by reacting the corresponding 1,2,4-benzothiadiazine 1,1-dioxide with a piperazine compound or alkylating 1,2,4-benzothiadiazine 1,1-dioxide whose corresponding 3-position is substituted by a piperazinyl group. The above compound has superior antihypertensive activity separated from diuretic, antidiuretic and hyperglycemic activities, and is free from side-effects.