反应详情

温度

65 °C

To a solution of ethyl 2-(4-chloro-2-fluorophenyl)-1H-imidazole-4-carboxylate 41 (175 g, 4.3 mol) in THF (1 L, 6 vol) and H2O (500 mL, 3 vol) was added NaOH (78 g, 1.95 mol, 3.0 eq), and the reaction was stirred at 65° C. for 48 h till it completed (checked by LC-MS). Adjust the mixture with 2 N HCl to pH=5, and product was separated out as a yellow solid, filtered to give 210 g wet cake, the wet cake was washed with H2O (300 mL), DCM (3×300 mL), PE (500 mL), and dried to afford 110 g pure 2-(4-chloro-2-fluorophenyl)-1H-imidazole-4-carboxylic acid 42 (CAS Reg. No. 1260649-87-3) (Scheme 15). 1H NMR (DMSO d6) δ: 12.8 (br s), 8.0, 7.9 (br s), 7.46, 7.4 (m),

1. customwas separated out as a yellow solid
2. filtrationfiltered
3. customto give 210 g wet cake
4. washthe wet cake was washed with H2O (300 mL), DCM (3×300 mL), PE (500 mL)
5. customdried