Hydrochloric Acid → Ethyl 2-chlorooxazole-4-carboxylate

Temperature

80 °C

To a mixture of tert-butyl nitrate (2.86 mL), copper(II) chloride (3.23 g) and acetonitrile (64 mL) was added ethyl 2-amino-1,3-oxazole-4-carboxylate obtained in Step A (2.50 g) at 60° C. The reaction mixture was heated at 80° C. for 3 hr, and cooled to room temperature. The reaction mixture was poured into 1 M hydrochloric acid, and the mixture was extracted with dichloromethane. The extract was washed with saturated brine, and dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate/hexane) to give the title compound (1.90 g).

1. temperaturecooled to room temperature
2. extractionthe mixture was extracted with dichloromethane
3. washThe extract was washed with saturated brine
4. dry with materialdried over anhydrous magnesium sulfate
5. customthe solvent was evaporated under reduced pressure
6. customThe residue was purified by silica gel column chromatography (ethyl acetate/hexane)

ORD record

ord-55e91de54ad14956aee29cd62bc44e9e

Source dataset

uspto-grants-2015_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09085578B2