反应详情

1-Methyl-5-(3-aminophenyl)-tetrazole (24.0 g, 137 mmol) was dissolved in dichloromethane (1.4 L) and 2,6-lutidine (44.1 g, 411 mmol) was added. Phenyl chloroformate (21.2 g, 136 mmol) was added in 4 portions over 15 minutes, and the mixture was stirred for 1.5 hours. The mixture was poured into 1N aqueous hydrochloric acid (200 mL) and the mixture was extracted three times with dichloromethane (200 mL). The combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, and concentrated under vacuum. The crude brown material was dissolved in hot toluene, filtered, and allowed to precipitate at 0° C. to give a white solid (34.1 g). The filtrate was concentrated and recrystallized again from toluene to give an additional crop of off-white crystals (3.44 g, 93% total). 1H NMR (300 MHz, CDCl3), δ10.51 (bs, 1H), 8.01 (s, 1H), 7.71 (dt, J=7, 2 Hz, 1H), 7.55 (m, 2H), 7.41 (m, 2H), 7.24 (m, 2H), 4.14 (s, 3H).

1. extractionthe mixture was extracted three times with dichloromethane (200 mL)
2. washThe combined organic layers were washed with saturated aqueous sodium chloride
3. dry with materialdried over sodium sulfate
4. concentrationconcentrated under vacuum
5. dissolutionThe crude brown material was dissolved in hot toluene
6. filtrationfiltered
7. customto precipitate at 0° C.