Water → ethyl 1-(2-propynyl)-3-trifluoromethyl-1H-pyrrole-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

1 g of ethyl 3-trifluoromethyl-1H-pyrrole-4-carboxylate of Step A was introduced into 10 ml of tetrahydrofuran, followed, at 0° C. by 240 mg of sodium hydride at 50% in vaseline oil in small portions. After stirring for 30 minutes at 20° C. and cooling to 0° C., a solution of 0.45 ml of propargyl bromide in 1 ml of tetrahydrofuran was added with stirring for 30 minutes at 0° C., then for 1 hour at 20° C., followed by cooling again to 0° C. A little sodium hydride was added then 0.45 ml of propargyl bromide in solution in 1 ml of tetrahydrofuran with stirring at 0° C. The mixture was poured into water and extracted with methylene chloride. The extracts were concentrated to dryness by distilling under reduced pressure and the residue was chromatographed over silica. Elution with a mixture of hexane and ethyl acetate (8-2) yielded 0.950 g of ethyl 1-(2-propynyl)-3-trifluoromethyl-1H-pyrrole-4-carboxylate melting at 58° C.

Provenance & Evidence