Trifluoroacetic acid → Methyl 4-formyl-3-hydroxybenzoate

反応式

[OH:1][C:2]1[CH:3]=[C:4]([CH:9]=[CH:10][CH:11]=1)[C:5]([O:7][CH3:8])=[O:6].FC(F)(F)[C:14](O)=[O:15]>>[CH:14]([C:3]1[C:2]([OH:1])=[CH:11][CH:10]=[CH:9][C:4]=1[C:5]([O:7][CH3:8])=[O:6])=[O:15].[CH:14]([C:11]1[CH:10]=[CH:9][C:4]([C:5]([O:7][CH3:8])=[O:6])=[CH:3][C:2]=1[OH:1])=[O:15]

参加物

反応物 2

HCID 6422Trifluoroacetic acid

HCID 88068Methyl 3-Hydroxybenzoate

生成物 2

HCID 14395860Methyl 4-formyl-3-hydroxybenzoate

HCID 14774772Methyl 2-formyl-3-hydroxybenzoate

実験手順

Methyl 3-hydroxybenzoate (75.5 g) is dissolved in trifluoroacetic acid (2 L), thereto is added hexamethylene-tetramine tetramine (141.4 g) at room temperature, and the mixture is heated under reflux for 3 hours. The reaction solution is concentrated under reduced pressure and water is added to the resulting residue. The mixture is adjusted to pH 8 with potassium carbonate and sodium hydrogen carbonate, diluted with water and extracted with ethyl acetate. The organic layer is washed with saturated brine, dried over sodium sulfate, and evaporated to remove the solvent under reduced pressure. The resulting residue is purified by silica gel column chromatography (eluent: hexane/ethyl acetate=8/1, 5/1, and then 2/1) to give methyl 2-formyl-3-hydroxybenzoate (54.6 g) (ESI-MS m/z: 179[M−H]−) and methyl 4-formyl-3-hydroxybenzoate (4.4 g) (ESI-MS m/z: 179[M−H]−).