反应详情

Ethyl 5-(4-bromophenyl)-1-methyl-1H-[1,2,3]triazole-4-carboxylate (from step 3b, 2.0 g, 6.45 mmol) was dissolved in 30 mL of THF and 0.5N lithium hydroxide solution (15 mL) was added. The mixture was stirred at room temperature for 10 hrs and solvents were evaporated. The residue was dissolved in water (30 mL) and filtered. The filtrate was treated with hydrochloric acid (2N, 4 mL). The white solid was filtered and dried to give 5-(4-bromo-phenyl)-1-methyl-1H-[1,2,3]triazole-4-carboxylic acid (1.82 g, 100% yield). LC-MS calcd for C10H8BrN3O2 (m/e) 283.0, obsd 282.0 (M−H); 1H-NMR (400 MHz, DMSO-d6) δ ppm 3.89 (s, 3H), 7.50 (d, J=8.4 Hz, 2H), 7.75 (d, J=8.4 Hz, 2H), 12.95 (br s, 1H).

1. customsolvents were evaporated
2. dissolutionThe residue was dissolved in water (30 mL)
3. filtrationfiltered
4. additionThe filtrate was treated with hydrochloric acid (2N, 4 mL)
5. filtrationThe white solid was filtered
6. customdried