反应详情

A solution of ethyl 3-(4-bromo-2-fluorobenzimidamidooxy)acrylate 25 (300 g, 0.91 mol, 1 eq) in diphenyl oxide (900 mL, 3 vol) was stirred at 190° C. under N2 for 1 h and checked by LC-MS (no 25 remaining) Cooled the mixture to rt and TBME (600 mL, 2 vol of 25) was added, and then PE (1.8 L, 6 vol of 25) was dropwise added to separate out solids. The mixture was stirred at rt for 20 min, and filtered to give 160 g wet cake. The wet cake was washed with PE (1 L) and dried to afford 120 g ethyl 2-(4-bromo-2-fluorophenyl)-1H-imidazole-4-carboxylate 26 with 92% LC purity as brown solids.

1. customto separate out solids
2. filtrationfiltered
3. customto give 160 g wet cake
4. washThe wet cake was washed with PE (1 L)
5. customdried