Trifluoroacetic anhydride → 1-(5-Bromo-4-(4-trifluoromethylthiazol-2-yl)pyridin-2-yl)-3-ethylurea

Participants

Reaction Steps

To a mixture of 1-(5-bromo-4-(4-hydroxy-4-(trifluoromethyl)-4,5-dihydrothiazol-2-yl)pyridin-2-yl)-3-ethylurea (Intermediate 41, 2.2 g, 5.32 mmol) in DCM (30 mL), TFAA (1.128 mL, 7.99 mmol) followed by TEA (1.113 mL, 7.99 mmol) were added. The reaction mixture was allowed to stir overnight at room temperature, then another 150 uL of TEA and TFAA were added and the reaction mixture was stirred for additional 3 h. The reaction was concentrated under reduced pressure, and the residue was partitioned between water and ethyl acetate. The layers were separated, and the organic layer was washed with sodium bicarbonate solution, water and brine, then dried over magnesium sulfate and concentrated under reduced pressure. The light yellow solid obtained was purified by normal phase (1% MeOH in dichloromethane to 3% MeOH in dichloromethane) to give 520 mg of the product. MS (ESP): 396 (M+1) for C12H10BrN3O; NMR: 1.07 (t, 3H); 3.11-3.17 (m, 2H); 7.24 (t, 1H); 8.35 (s, 1H); 8.50 (s, 1H); 8.77 (s, 1H); 9.34 (s, 1H)

Provenance & Evidence