| 摘要 |
There are provided compounds of the following formula, and non-toxic salts thereof: <CHEM> wherein R is a heteroaroyl group which contains a nitrogen, sulfur or oxygen atom and which may be substituted with a lower alkyl group, an aralkyl group, an acyl group or a halogen atom; an alkyl sulfonyl group; a benzenesulfonyl group which may be substituted with a lower alkyl group, a lower alkoxy group, a nitro group or a halogen atom; or a cycloalkanoyl group which may be substituted with a lower alkyl group, a lower alkenyl group, a halogen atom, a halogeno lower alkenyl group (e.g. 2,2-dichlorovinyl), a phenyl group, a halogeno-phenyl group (e.g. p-chlorophenyl), a phenyl group substituted with a lower alkyl or lower alkoxy group (e.g. p-tolyl, p-methoxyphenyl) a formyl group, a hydroxy group, an amino group, a carboxyl group, an aminomethyl group or an oxo group. |
