Potassium Carbonate → Ethyl 5-ethyl-2-(2-nitroanilino)-thiophene-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

o-Fluoronitrobenzene (56.4 g, 0.4 mol) and ethyl 2-amino-5-ethylthiophene-3-carboxylate (100 g, 0.5 mol) were dissolved in dry dimethylsulphoxide (320 ml). The stirred solution, under nitrogen, was heated in an oil bath. When the internal temperature reached 60° C., potassium carbonate (55 g, 0.4 mol) was added and the mixture stirred at 100° C. until GLC indicated that all the o-fluoronitrobenzene had been consumed (6.5 hours). The mixture was then poured onto ice-water, acidified with concentrated hydrochloric acid and extracted with methylene chloride. The combined extracts were washed with water, dried (MgSO4) and the solvent evaporated to give a red semi-solid which was recrystallised from ethanol to give the title product as a solid (m.p. 66°-68° C.).

Provenance & Evidence