반응 #42612
ord-81b48af23f104facb77c3ddc8f18f085
반응 조건
후처리
- 1온도The mixture was then heated under agitation
- 2온도to reflux for 16 hours
- 3기타The reaction solution was then evaporated to dryness
- 4기타The mixture was separated
- 5추출the aqueous phase was extracted twice with ethyl acetate
- 6세척washed with water and brine
- 7농축The resulting yellow solution was concentrated to ˜50 ml
- 8기타to precipitate out
- 9여과The solid was filtered off
- 10세척washed with ethanol and diethyl ether
- 11기타The mother liquor was then evaporated to dryness
- 12농축concentrated to ˜50 ml
- 13기타An off-white solid precipitated out
- 14온도The mixture was cooled in an ice bath
- 15여과the solid was filtered off
- 16세척washed with ethanol and diethyl ether
실험 절차
To a 250 ml 3-neck round bottom flask was added (20 g, 0.3332 moles) urea, (150 ml) ethanol and (42.42 g, 0.2175 moles, 0.65 eq) ethylbromopyruvate. The mixture was then heated under agitation to reflux for 16 hours. The reaction solution changed from yellow to red in color. The reaction solution was then evaporated to dryness and the crude product was taken up in (50 ml) water and (150 ml) ethyl acetate. The pH was adjusted from 1 to 10 using 2N sodium hydroxide, changing the biphasic mixture a dark red. The mixture was separated and the aqueous phase was extracted twice with ethyl acetate. The organic layers were then combined and washed with water and brine. The resulting yellow solution was concentrated to ˜50 ml, causing an off-white solid to precipitate out. The solid was filtered off and washed with ethanol and diethyl ether. The mother liquor was then evaporated to dryness and the resulting oily solid was taken up in (150 ml) ethyl acetate and concentrated to ˜50 ml. An off-white solid precipitated out. The mixture was cooled in an ice bath, and the solid was filtered off and washed with ethanol and diethyl ether to give ethyl 2-amino-1,3-oxazole-4-carboxylate (14.79 g).