Dimethylformamide → Methyl 5-formyl-2-methylfuran-3-carboxylate

反応式

P(Cl)(Cl)(Cl)=O.[CH3:6][O:7][C:8]([C:10]1[CH:14]=[CH:13][O:12][C:11]=1[CH3:15])=[O:9].[OH-].[Na+].CN([CH:21]=[O:22])C>>[CH3:6][O:7][C:8]([C:10]1[CH:14]=[C:13]([CH:21]=[O:22])[O:12][C:11]=1[CH3:15])=[O:9]

参加物

反応物 4

HCID 6228Dimethylformamide

HCID 14798Sodium Hydroxide

HCID 24813Phosphorus oxychloride

HCID 80237Methyl 2-methylfuran-3-carboxylate

生成物 1

HCID 2779820Methyl 5-formyl-2-methylfuran-3-carboxylate

実験手順

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+).