Patent number: 5093493
Abstract: Compounds of formula (I) or pharmaceutically acceptable salts thereof: ##STR1## wherein: R.sub.1 is hydrogen, C.sub.1-6 alkyl, phenyl or phenyl C.sub.1-4 alkyl wherein the phenyl moiety is optionally substituted by one or more C.sub.1-6 alkyl, C.sub.1-6 alkoxy, C.sub.1-6 alkylthio, hydroxy, C.sub.2-7 alkanoyl, halo, trifluoromethyl, nitro, amino optionally substituted by one or two C.sub.1-6 alkyl groups or by C.sub.2-7 alkanoyl, cyano, carbamoyl or carboxy groups;R.sub.2, R.sub.3 and R.sub.4 are independently selected from hydrogen, C.sub.1-6 alkyl, C.sub.1-6 alkoxycarbonyl, C.sub.1-6 alkylthio, C.sub.2-7 alkanoyl, trifluoromethyl, cyano, carbamoyl and carboxy, and phenyl or phenyl C.sub.1-4 alkyl in which any phenyl moiety is optionally substituted by C.sub.1-6 alkyl, C.sub.1-6 alkoxy, C.sub.1-6 alkoxy carbonyl, C.sub.1-6 alkylthio, hydroxy, C.sub.2-7 alkanoyl, chloro, fluoro, trifluoromethyl, nitro or amino optionally substituted by one or two C.sub.1-6 alkyl groups or by C.sub.
Type:
Grant
Filed:
March 12, 1990
Date of Patent:
March 3, 1992
Assignee:
Beecham Group p.l.c.
Inventors:
Mervyn Thompson, Ian T. Forbes, Christopher N. Johnson