Acetone → Ethyl 3,3-dimethyloxirane-2-carboxylate

Temperature

-10 °C

To a stirred solution of propan-2-one (11.52 ml, 157 mmol) and ethyl 2-chloroacetate (25.04 ml, 235 mmol) in dry diethyl ether (125 ml) at −10° C. under nitrogen was added sodium ethoxide (10.66 g, 157 mmol) portionwise, keeping the temperature below 5° C. After addition was complete, the mixture was stirred for two hours at −10° C., whereafter the reaction was continued at room temperature for three hours. The reaction mixture was quenched with saturated aqueous ammonium chloride, the phases were separated, and the aqueous layer was extracted with diethyl ether (100 ml). The combined organic phases were dried over Na2SO4 and evaporated in vacuo). The resulting residue was purified by vacuum distillation. The major fraction (−25 mbar, 82° C.-85° C., 14.3 g) consisted of the desired product, containing 6.4 mol % ethyl chloroacetate. This was used in the next step without further purification.

1. customthe temperature below 5° C
2. additionAfter addition
3. waitwas continued at room temperature for three hours
4. customThe reaction mixture was quenched with saturated aqueous ammonium chloride
5. customthe phases were separated
6. extractionthe aqueous layer was extracted with diethyl ether (100 ml)
7. dry with materialThe combined organic phases were dried over Na2SO4
8. customevaporated in vacuo)
9. distillationThe resulting residue was purified by vacuum distillation
10. customThe major fraction (−25 mbar, 82° C.-85° C., 14.3 g)
11. additioncontaining 6.4 mol % ethyl chloroacetate
12. customThis was used in the next step without further purification

ORD record

ord-1b9034b13e5541c79b9c7eab7f7c5270

Source dataset

uspto-grants-2014_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08669208B2