反应详情

温度

20 °C

7.4 g of ethyl 4,4,4-trifluoro-(E)-butenoate (E. T. McBee, J. Am. Soc. Vol. 76 p. 3724 (1924)) and 8.6 g of tosylmethyl isocyanide were introduced into 200 ml of a mixture of dimethylsulfoxide and ethyl ether (1-2) and then 2.9 g of sodium hydride at 50% in vaseline were added in small portions. Hydrogen evolved and after stirring for 30 minutes at 20° C., a few drops of acetic acid were added. The mixture was poured into a mixture of water and ice and was extracted with ether. The extracts were concentrated to dryness by distilling under reduced pressure and the residue was chromatographed over silica. Eluting with a mixture of hexane and ethyl acetate (7-3) to yielded 6.6 g of ethyl 3-trifluoromethyl-1H-pyrrol-4-carboxylate melting at 165° C.

1. extractionwas extracted with ether
2. concentrationThe extracts were concentrated to dryness
3. distillationby distilling under reduced pressure
4. customthe residue was chromatographed over silica
5. washEluting with a mixture of hexane and ethyl acetate (7-3)