Hydrochloric Acid → Benzyl carbamate

Temperature

100 °C

A mixture of (2-cyano-ethyl)-carbamic acid benzyl ester (2.6 g, 12.7 mmol), sodium azide (2.48 g, 38 mmol) and triethylamine hydrochloride (2.62 g, 19 mmol) in NMP (96 mL) was stirred at 100° C. under Ar. After 24 h, the reaction was cooled to room temperature. Additional sodium azide (1.24 g, 19 mmol) and triethylamine hydrochloride (1.3 g, 9.5 mmol) was added to the reaction mixture and the solution was heated to 100° C. under Ar. After 18 h, the reaction was diluted with water (100 mL). 1M HCl was added dropwise until the pH was slightly acidic (˜pH 4). The solution was extracted with EtOAc (3×100 mL). The combined organic layers were washed with water (3×100 mL) and brine (100 mL), dried over MgSO4, filtered and concentrated in vacuo to yield a brown oil. Flash chromatography on silica gel (0-15% MeOH in CH2Cl2) yielded 1.1 g of crude 2-(1H-tetrazol-5-yl)-ethyl]-carbamic acid benzyl ester (˜70% pure).

1. temperaturethe reaction was cooled to room temperature
2. temperaturethe solution was heated to 100° C. under Ar
3. waitAfter 18 h
4. extractionThe solution was extracted with EtOAc (3×100 mL)
5. washThe combined organic layers were washed with water (3×100 mL) and brine (100 mL)
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customto yield a brown oil

ORD record

ord-2c136a13d3024ea99f1bab752ec2a92c

Source dataset

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08552205B2