Water → Diethyl 2-((isopropyl)amino)thiophene-3,4-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

Ethoxycarbonylmethylene triphenyl phosphorane (33.8 g) in dry THF (200 ml) was treated with isopropyl isothiocyanate (10.1 g) at 65° C. for 16 h under nitrogen. The mixture was cooled to −78° C. and ethyl bromo-pyruvate (19.5 g) was added. The reaction was allowed to warm slowly to room temperature. After 24 h at room temperature more ethyl bromo-pyruvate (3.17 g) was added and the mixture was stirred at room temperature for 16 h. The reaction was poured into water (1.5 L) and extracted into ether. Drying and evaporation gave an oil which was chromatographed (SiO2/5:1 isohexane-ethyl acetate) to afford the subtitle compound (21.2 g). δ 1HCDCl3 1.23-1.43 (12H, m), 3.46 (1H, m), 4.2-4.35 (4H, m), 6.50 (1H, s), 7.52 (1H, br.d)

Provenance & Evidence