PYRIDOPYRIMIDINE DERIVATIVES AND PROCESS FOR THEIR PREPARATION

摘要

New compounds of formula (I) [where R1 represents a phenyl group optionally substituted by a lower alkyl group, a group of formula (II) (where each of R5 and R6 represents H, a lower alkyl group, or a methyl group substituted by a phenyl group, or R5 and R6 taken together represent a C4 - C6 alkylene group) or a group of formula (III) (where n is 2 or 3, R7 represents H, a lower alkyl group, an aralkyl group, a lower alkoxycarbonyl group, an aralkyloxycarbonyl group or an acyl group); R2 represents H or a lower alkyl group; R3 represents H, a lower alkyl group, an aralkyl group, an aryl group, a lower alkyl group substituted by a hydroxyl group, a lower alkyl group substituted by a lower alkoxy group or a lower alkyl group substituted by a tetrahydropyranoxy group; R4 is H, a lower alkyl group or an aralkyl group] are disclosed together with a method for their preparation. The compounds are useful as herbicides.