反应详情

The solution of ethyl 2-(1-(3-bromophenyl)-3-oxobutan-2-ylamino)-2-oxoacetate (1.0 g, 2.9 mmol) in POCl3 (10 mL) was refluxed overnight. The mixture was concentrated, treated with H2O (40 mL), neutralized with aqueous NaHCO3 and extracted with EtOAc (3×20 mL). The combined organic layers were washed with H2O (20 mL), dried over Na2SO4, filtered, and concentrated to afford the crude product, which was purified by silica gel column chromatography (EtOAc:Petroleum ether=1:5) to afford ethyl 4-(3-bromobenzyl)-5-methyloxazole-2-carboxylate as a yellow oil (0.5 g, 51%). MS (ES+) C14H14BrNO3 requires: 323, 325 found: 324 [M+H]+, 326 [M+2+H]+(1:1).

1. concentrationThe mixture was concentrated
2. additiontreated with H2O (40 mL)
3. extractionextracted with EtOAc (3×20 mL)
4. washThe combined organic layers were washed with H2O (20 mL)
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated
8. customto afford the crude product, which
9. customwas purified by silica gel column chromatography (EtOAc:Petroleum ether=1:5)