Thiourea → 5-Thiazolecarboxylic acid, 2-amino-4-(trifluoromethyl)-, ethyl ester

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Reaction Steps

To a solution of ethyl 2-chloro-4,4,4-trifluoroacetoacetate (50.0 g, 230 mmol) in ethanol (250 mL) was added thiourea (17.5 g, 230 mmol). The resulting mixture was heated at reflux for 3 h, at which time TLC indicated a complete reaction. The mixture was concentrated in vacuo, and the residue dissolved in ether. The organic layer was successively washed with aqueous sodium bicarbonate, and brine, then dried over magnesium sulfate and concentrated in vacuo. The resulting solid was recrystalized with ethyl acetate and hexanes to give white crystals (41.64 g, 75% yield). 1H NMR (MeOD-d4, 300 MHz): δ 4.26 (q, J=7.1 Hz, 2H), 1.31 (t, J=7.1 Hz, 3H).

Provenance & Evidence