Methylhydrazine → HCID 178481857, compound

To a solution of methyl 4,4-difluoro-3-oxobutanoate (64 g, 0.38 mol) in methanol (500 mL) was added methylhydrazine (20.5 mL, 0.38 mol). The reaction mixture was left to stir overnight at room temperature. The volatiles were removed in vacuo, toluene was added (400 mL), the mixture was evaporated again, and this procedure was repeated. The resulting solid residue was purified chromatographically on silica gel using ethyl acetate/dichloromethane mixture (1:2, Rf=0.35). The resulting oil was crystallized from ether (200 mL) and dried under the vacuum of a membrane pump (10 mm Hg) for 3 h to give 28 g (49.8%) of the title product.