Alkylphosphonamidate herbicides

Abstract

Herbicidal compounds have the formula ##STR1## in which R is C.sub.3 -C.sub.6 alkyl or C.sub.3 -C.sub.6 cycloalkyl; X is oxygen or sulfur; R.sub.1 is C.sub.1 -C.sub.12 alkyl, C.sub.3 -C.sub.6 cycloalkyl optionally substituted with up to two C.sub.1 -C.sub.3 alkyl groups, phenyl, or substituted phenyl having from 1 to 2 substituents selected from halo, nitro, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 thioalkyl, C.sub.3 -C.sub.4 alkenyl, C.sub.1 -C.sub.4 alkoxycarbonyl, and phenyl; R.sub.2 is hydrogen, C.sub.1 -C.sub.6 alkyl or C.sub.3 -C.sub.6 cycloalkyl; and R.sub.3 is C.sub.2 -C.sub.6 alkyl, C.sub.3 -C.sub.6 cycloalkyl, phenyl or substituted phenyl having from 1 to 2 substituents selected from C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkyl and halogen; provided that if R.sub.2 is hydrogen, R.sub.3 is not phenyl or substituted phenyl; or R.sub.2 and R.sub.3 taken together with the nitrogen atom form a 4-8 membered ring, optionally including an oxygen heteroatom.

Dependencies are inferred from the claim text.