ethyl 4,4-difluorobut-2-ynoate

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 10.2 g (0.068 mol) of ethyl 4,4-difluoro-2-butynoate in 20 ml of methylene chloride was added dropwise to a stirred solution of 4 ml (0.075 mol) of methylhydrazine in 80 ml of methylene chloride cooled to -78° C. The resultant reaction mixture was stirred overnight and subsequently concentrated in vacuo to afford 8.63 g of a clear, yellow oil. The oil was dissolved in ethyl acetate and washed with 10% aqueous sodium bicarbonate. The organic layer was dried, concentrated and recrystallized from carbon tetrachloride to give 2.2 g (21.7% yield) of a white crystalline solid, m.p. 115°-119° C. The resultant reaction mixture subsequently concentrated in vacuo to afford 8.63 g of a clear, yellow oil washed with 10% aqueous sodium bicarbonate The organic layer was dried concentrated recrystallized from carbon tetrachloride