Benzyl Alcohol → Benzyl carbamate

Temperature

0 °C

To a solution of carboxylic acid 20 (1.88 g, 9.58 mmol) and triethylamine (1.65 mL, 1.26 g, 12.5 mmol) in acetone (30 mL) at 0° C. was added ethyl chloroformate (0.92 mL, 1.0 g, 9.6 mmol) dropwise over several minutes. After the addition was complete the solution was stirred for 1 hour at 0° C. A solution of sodium azide (1.87 g, 28.7 mmol) in water (30 mL) was added and the reaction mixture was stirred for an additional hour at 0° C. The solution was poured into ice water and the resulting mixture was extracted with ethyl acetate (4×50 mL). The combined organic extracts were washed sequentially with sodium bicarbonate and brine and then dried over sodium sulfate. Concentration gave a residue which was dissolved in dry benzene (50 mL) and heated under reflux for 1.5 hours. Benzyl alcohol (2.07 g, 19 mmol) was added and heating under reflux was continued for an additional 2.5 hours. Concentration gave a pale yellow oil which was crystallized from Et2O/hexane to give the title compound 21(2.1 g, 73%) as colorless crystals: mp 73°-76° C.

1. additionAfter the addition
2. stirringthe reaction mixture was stirred for an additional hour at 0° C
3. extractionthe resulting mixture was extracted with ethyl acetate (4×50 mL)
4. washThe combined organic extracts were washed sequentially with sodium bicarbonate and brine
5. dry with materialdried over sodium sulfate
6. concentrationConcentration
7. customgave a residue which
8. temperatureheated
9. temperatureunder reflux for 1.5 hours
10. temperatureheating
11. temperatureunder reflux
12. waitwas continued for an additional 2.5 hours
13. concentrationConcentration
14. customgave a pale yellow oil which
15. customwas crystallized from Et2O/hexane

ORD record

ord-34b41d27cf444526911d3df6fa2d0a8c

Source dataset

uspto-grants-1997_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05650535