Ethyl bromopyruvate → Ethyl 2-(trifluoromethyl)-1,3-thiazole-4-carboxylate

Participants

Reaction Steps

A mixture of 2,2,2-trifluoroacetamide (7.12 g, 63 mmol) and Lawesson's reagent (15.3 g, 37.8 mmol) in THF (60 mL) was heated at reflux for 18 hours. The reaction was then cooled down to RT and treated with ethyl bromopyruvate (8.0 mL, 63 mmol). The reaction was stirred at reflux for an additional 18 hours, then concentrated under vacuum and diluted with ethyl acetate. This mixture was washed with water (1×) and brine (1×), dried over anhydrous magnesium sulfate, filtered and concentrated. The residue was purified by silica gel chromatography (8×11 cm, toluene, then second time with 120 g silica gel, hexane/ethyl acetate) to give the title material (4.47 g, 32%) as a pale yellow solid. 1H NMR (CDCl3, 400 MHz) δ 8.37 (s, 1H), 4.45 (q, J=7.0 Hz, 2H), 1.41 (t, J=7.0 Hz, 1H).

Provenance & Evidence