Sodium Bicarbonate → 1-(4-hydroxyphenyl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester
Reaktionsgleichung
[CH2:1]([O:3][C:4]([C:6]1[CH:7]=[N:8][N:9]([C:12]2[CH:17]=[CH:16][C:15]([O:18]C)=[CH:14][CH:13]=2)[C:10]=1[CH3:11])=[O:5])[CH3:2].C(=O)(O)[O-].[Na+]>ClCCl>[CH2:1]([O:3][C:4]([C:6]1[CH:7]=[N:8][N:9]([C:12]2[CH:13]=[CH:14][C:15]([OH:18])=[CH:16][CH:17]=2)[C:10]=1[CH3:11])=[O:5])[CH3:2]Komponenten
4
Versuchsvorschrift
1.0M Solution of borone tribromide in dichloromethane (35 ml) was added to a solution of 1-(4-methoxyphenyl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (3.0 g) in dichloromethane (12 ml) under ice cooling, and the mixture was stirred at the same temperature for three hours. After completion of the reaction, the reaction mixture was added to a saturated aqueous solution of sodium bicarbonate under ice cooling, a saturated aqueous solution of sodium bicarbonate was further added until the mixture was neutralized to pH 7 and extracted with chloroform three times. The organic layer was dried over anhydrous sodium sulfate and concentrated. The resulting residue was purified with silica gel column chromatography (chloroform/methanol) to give 1-(4-hydroxyphenyl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (2.33 g) as a white solid.