Cesium carbonate → ethyl 2-(1-((2,2-difluorocyclopropyl)methyl)-5-oxo-1H-1,2,4-triazol-4(5H)-yl)-4-methylthiazole-5-carboxylate

Participants

Reaction Steps

To a solution of ethyl 4-methyl-2-(5-oxo-1H-1,2,4-triazol-4(5H)-yl)thiazole-5-carboxylate (9.36 g, 36.8 mmol) in anhydrous N,N-dimethylformamide (150 mL) was added cesium carbonate (23.90 g, 73.70 mmol). The reaction mixture was stirred at ambient temperature for 30 min, followed by the addition of bromomethyl-2,2-difluorocyclopropane (6.00 g, 35.10 mmol) in N,N-dimethylformamide (50 mL). The reaction mixture was heated at 40° C. for 3 h and filtered. The solid was washed with ethyl acetate (100 mL). The filtrate was concentrated in vacuo to dryness. The residue was triturated with ethyl acetate (50 mL) to afford the title compound as a yellow solid (10.8 g, 98%): mp 146-148° C.; 1H NMR (300 MHz, DMSO-d6) δ 8.74 (s, 1H), 4.23 (t, J=7.1 Hz, 2H), 3.97-3.77 (m, 2H), 2.54 (s, 3H), 2.20-2.04 (m, 1H), 1.73-1.60 (m, 1H), 1.48-1.37 (m, 1H), 1.26 (t, J=7.1 Hz, 3H); 13C NMR (75 MHz, DMSO-d6) δ 161.8, 156.6, 154.0, 149.9, 132.2, 118.2, 114.4 (t), 61.6, 42.8 (d), 20.7 (t), 17.2, 14.9 (t), 14.5; MS (ES+) m/z 345.9 (M+1).

Provenance & Evidence