| abstract |
A process of severely damaging or killing unwanted plants, which comprises applying to the plants, or to the growth medium thereof, a herbicidally effective amount of pyrimidine compound of the formula: <IMAGE> or a herbicidal acid addition salt thereof, wherein R1 is an alkyl radical of 1 to 6 carbon atoms, cycloalkyl or alkenyl; R is a hydrogen atom or an alkyl or alkenyl radical of from 1 to 12 carbon atoms, which may be substituted by a phenyl radical; or R1 and R taken together form a trimethylene or tetramethylene radical; X is either (a) an -NR3R4 radical wherein each of the groups R2and R4 is a hydrogen atom or an alkyl or alkenyl radical of 1 to 3 carbon atoms or cycloalkyl, or -NR3R4 constitutes a pyrrolidinyl, piperidinyl or morpholinyl ring; or (b) a group -OR5 wherein R5 is an alkyl or alkenyl radical of 1 to 10 carbon atoms or cycloalkyl; and R6 and R7 each represent hydrogen or an alkyl or alkenyl radical of 1 to 8 carbon atoms, or cycloalkyl, or R6 and R7, taken together with the nitrogen atom to which they are attached constitute a pyrrolidinyl, piperidinyl, or morpholinyl ring; provided that R may be hydrogen only when X is an OR5 group. |