反应详情

To a solution of oxazole-5-carboxylic acid methyl ester (1.4 g, 11 mmol) in anhydrous THF (50 mL) at −40° C. under an argon atmosphere was slowly added a solution of LiHMDS (13.3 mL, 1 M in THF). After 1 h at −40° C., solid hexachloroethane (3.91 g, 16.5 mmol) was added. The mixture was then allowed to slowly warm to room temperature and stir for 16 h. The reaction was diluted with AcOEt/H2O (30 mL/10 mL). The organic layer was washed with brine, dried with MgSO4 and filtered. After removal of solvent the residue was silica gel column chromatographed (CH2Cl2/Cyclohexane: 1/1) to give 1.1 g of 2-chloro-oxazole-5-carboxylic acid methyl ester (62%) as a white solid. m.p.=35-50° C.

1. washThe organic layer was washed with brine
2. dry with materialdried with MgSO4
3. filtrationfiltered
4. customAfter removal of solvent the residue
5. customchromatographed (CH2Cl2/Cyclohexane: 1/1)