1-Methylimidazole → ethyl 1-methyl-1H-imidazole-2-carboxylate

Temperature

-20 °C

N-methylimidazole (320 g, 3.9 mol) was combined with 2 L acetonitrile and 1 L triethylamine in a 12 L flask equipped with a mechanical stirrer and the solution cooled to −20° C. Ethyl chloroformate (1000 g, 9.2 mol) was added with stirring, keeping the temperature between −20° C. and −25° C. The reaction was allowed to lowly warm to room temperature and stir for 36 h. Precipitated triethylamine hydrochloride was removed by filtration and the solution concentrated in vacuo at 65° C. The resulting oil was purified by distillation under reduced pressure (2 torr, 102° C.) to provide a white solid (360 g, 82% yield).

1. customequipped with a mechanical stirrer
2. customthe temperature between −20° C. and −25° C
3. temperatureto lowly warm to room temperature
4. stirringstir for 36 h
5. customPrecipitated triethylamine hydrochloride was removed by filtration
6. concentrationthe solution concentrated in vacuo at 65° C
7. distillationThe resulting oil was purified by distillation under reduced pressure (2 torr, 102° C.)

ORD record

ord-0af0c12a71574c4ab2e6ec57258eefa6

Source dataset

uspto-grants-2003_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06635417B1