Lithium Hexamethyldisilazide → tert-Butyl 1,3-thiazol-4-yl[(2,4,5-trifluorophenyl)sulfonyl]carbamate

Participants

Reaction Conditions

Reaction Steps

A solution of tert-butyl thiazol-4-ylcarbamate (3.46 g, 17.3 mmol) in tetrahydrofuran (150 mL) at −78° C. was treated with lithium bis(trimethylsilyl)amide (1.0 M solution in tetrahydrofuran, 20.8 mL, 20.8 mmol). The resulting mixture was stirred at −78° C. for 0.5 h, allowed to warm to ambient temperature and stirred for a further 0.5 h. The reaction mixture was cooled to −78° C. and treated with a solution of 2,4,5-trifluorobenzene-1-sulfonyl chloride (3.99 g, 17.3 mmol) in tetrahydrofuran (30 mL). The resulting mixture was stirred at −78° C. for 4 h, allowed to warm to ambient temperature and stirred for a further 16 h. The reaction mixture was diluted with ethyl acetate (300 mL) and washed with saturated aqueous ammonium chloride (2×150 mL) and brine (2×150 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was purified by column chromatography eluting with a gradient of ethyl acetate in hexanes to afford tert-butyl thiazol-4-yl((2,4,5-trifluorophenyl)sulfonyl)carbamate as a beige solid in 62% yield (4.23 g): 1H NMR (300 MHz, CDCl3) δ 8.79-8.75 (m, 1H), 8.06-7.96 (m, 1H), 7.53-7.48 (m, 1H), 7.15-7.04 (m, 1H), 1.34 (s, 9H); MS (ES+) m/z 394.7 (M+1).

Provenance & Evidence