Ethyl Acetate → 4-Trifluoromethyl-2-vinyl-thiazole-5-carboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of thiazole IV (17.4 g, 57.3 mmol) in toluene (150 mL) was added tetrakis(triphenylphosphine)palladium(0) (1.32 g, 1.14 mmol), tributyl(vinyl)tin (18.4 mL, 63.0 mmol), and 2,6-di-t-butyl-4-methyl phenol (catalytic). This mixture was stirred at 120° C. in a sealed tube for 25 min. The mixture was then allowed to come to 25° C. Ethyl acetate (250 mL) was added and the mixture was washed with 1 N aqueous NaOH (2×150 mL), saturated aqueous NaCl (1×150 mL), dried over MgSO4 and concentrated in vacuo to give a brown oil. Purification by flash chromatography (silica, 0-10% ethyl acetate/hexane) gave the 2-vinyl thiazole III (11.0 g, 76%) as a yellow oil. 1H NMR (CDCl3, 300 MHz): δ 6.88 (dd, J=11.0, 17.6 Hz, 1H), 6.20 (d, J=17.6 Hz, 1H), 5.74 (d, J=11.0 Hz, 1H), 4.38 (q, J=7.2 Hz, 2H), 1.37 (t, J=7.1 Hz, 3H).

Provenance & Evidence