反应详情

Phosphorus oxychloride (33 ml) is added dropwise to a solution of 2-methyl-furan-3-carboxylic acid methyl ester (25.0 g) in DMF (75 ml) under nitrogen at 0° C. After 3 h 30 at 40° C., the reaction mixture is slowly poured onto water at 0° C. and NaOH 5 N is added carefully. The mixture is extracted three times with diethyl ether. The combined organic phases are washed with a saturated aqueous solution of NaHCO3, dried over Na2SO4 and concentrated in vacuo. The crude product is purified by chromatography on silica gel eluting with a mixture of diethyl ether and ethyl acetate (3:1) to yield 5-formyl-2-methyl-furan-3-carboxylic acid methyl ester (22.36 g) as a yellow solid. MS (HPLC/MS): 169 (MH+).

1. additionthe reaction mixture is slowly poured onto water at 0° C.
2. extractionThe mixture is extracted three times with diethyl ether
3. washThe combined organic phases are washed with a saturated aqueous solution of NaHCO3
4. dry with materialdried over Na2SO4
5. concentrationconcentrated in vacuo
6. customThe crude product is purified by chromatography on silica gel eluting with a mixture of diethyl ether and ethyl acetate (3:1)