Reaction of 2-cyano-4-methoxy-6-methyl- (I), 4-cyano-6-methoxy-2-methyl- (II), 5-cyano-4-methoxy-2-methyl- (III), and 5-cyano-4,6-dimethoxy-2-methylpyrimidine (IV) with Grignard reagents is described. While 2-cyano and 4-cyano derivatives (I, II) were transformed to the corresponding pyrimidinyl ketones as expected, 5-cyano derivatives (III, IV) were converted to the addition products, 5-cyano-6-ethyl-1,6-dihydro-4-methoxy-2-methyl- (VIIa) and 5-cyano-2-ethyl-1,2-dihydro-4,6-dimethoxy-2-methylpyrimidine (XI), respectively.