Methyl chloroformate → methyl 3-cyclopropylpropynoate

Temperature

-78 °C

To a solution of cyclopropyl acetylene (10.0 g, 148 mmol) in 50 mL of ethyl ether at −78° C. under argon was added methyllithiium (1.4 M in ethyl ether, 107 mL, 150 mmol). This solution was stirred at −78° C. for 1 h. Methyl chloroformate (12.0 mL, 154 mmol) was added. The reaction mixture was warmed to room temperature in 2 h and was quenched with water. The organic layer was separated. The aqueous layer was extracted with ethyl ether (50 mL×3). The combined organic layer was dried over sodium sulfate and evaporated to give cyclopropyl-propynoic acid methyl ester as a yellow oil (13.25 g, 72%).

1. temperatureThe reaction mixture was warmed to room temperature in 2 h
2. customwas quenched with water
3. customThe organic layer was separated
4. extractionThe aqueous layer was extracted with ethyl ether (50 mL×3)
5. dry with materialThe combined organic layer was dried over sodium sulfate
6. customevaporated

ORD record

ord-3c5acd34bb5e410db624659553e1c648

Source dataset

uspto-grants-2006_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07119102B2