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

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).

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

ORD-Eintrag

ord-5e337fec8aff45468ee3f6820a93d5cf

Quelldatensatz

uspto-grants-2005_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06949546B2