Hydrochloric Acid → phenyl 3-(1-methyl-1H-tetraazol-5-yl)phenylcarbamate

Participants

Reaction Steps

In a dry flask of 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, then the reaction was stirred for 1.5 hours. The reaction was poured into 1N aqueous hydrochloric acid (200 mL) and the mixture was extracted with dichloromethane three times (200 mL). The combined organic layers were washed with brine, dried with sodium sulfate, filtered, and concentrated in vacuo. The crude brown material was dissolved in hot toluene, filtered, and allowed to precipitate at 0° C. to give 34.1 g of a white solid. The filtrate was concentrated and recrystallized from toluene again to give an additional crop of off-white crystals (3.44 g, 93% total). 1H NMR (300 MHz, CDCl3), δ: 10.51 (bs, 1H), 8.01 (s, 1H), 7.71 (dt, J=7, J′=2, 1H), 7.55 (m, 2H), 7.41 (m, 2H), 7.24 (m, 2H), 4.14 (s, 3H).

Provenance & Evidence