A compound of the formula: ##STR1## wherein R.sup.1 is a C.sub.1 -C.sub.6 alkyl group and R is a hydrogen atom or a C.sub.1 -C.sub.6 alkyl group, and their salts, which are useful as cerebral vasodilator; and a compound of the formula: ##STR2## wherein R.sup.2 is a hydrogen atom or a C.sub.1 -C.sub.6 alkyl group, R.sup.3 is a hydrogen atom or the formula: --CO.sub.2 R.sup.1 (R.sup.1 is a C.sub.1 -C.sub.6 alkyl group) and W is an oxygen atom, an imino group or ##STR3## but not an imino group in case that R.sup.3 is a hydrogen atom, which are intermediates of the compound (I), useful per se as cerebral vasodilator and/or antihypertensive agents.
公式:##STR1## 其中R1是C1-C6烷基,R是氢原子或C1-C6烷基,它们的盐对于脑血管扩张剂很有用;以及公式:##STR2## 其中R2是氢原子或C1-C6烷基,R3是氢原子或公式:--CO2R1(R1是C1-C6烷基),W是氧原子,亚
氨基或##STR3##但在R3是氢原子的情况下不是亚
氨基,它们是化合物(I)的中间体,本身对于脑血管扩张剂和/或降压剂很有用。