Application of the Vilsmeier formylation reaction to 4-methylpyrimidin-2-one (4) followed by treatment with hydroxylamine gave 4-(isoxaxol-4-yl) pyrimidin-2-one (5), which was transformed to 4-(cu-formylcyanomethyl)-pyrimidin-2-one (6) by rearrangement with alkali in 539$ overall yield (from 4). Methylation of 6 with NaH and Me1 in dimethylformamide gave 4- (~-formylcyanomethyI)-l-methylpyrimidin-2-one(2) in 76% yield.
