Sulfuric Acid → Prop-2-yn-1-yl [3-methyl-1-(4-methylpyridin-3-yl)-5-phenyl-1H-pyrazol-4-yl]acetate

Reaction equation

[CH2:1](O)[C:2]#[CH:3].S(=O)(=O)(O)O.[CH3:10][C:11]1[C:15]([CH2:16][C:17]([OH:19])=[O:18])=[C:14]([C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=2)[N:13]([C:26]2[CH:27]=[N:28][CH:29]=[CH:30][C:31]=2[CH3:32])[N:12]=1>>[CH3:10][C:11]1[C:15]([CH2:16][C:17]([O:19][CH2:3][C:2]#[CH:1])=[O:18])=[C:14]([C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=2)[N:13]([C:26]2[CH:27]=[N:28][CH:29]=[CH:30][C:31]=2[CH3:32])[N:12]=1

Participants

Reactant 3

HCID 1118Sulfuric Acid

HCID 7859Propargyl alcohol

HCID 68818330[3-Methyl-1-(4-methylpyridin-3-yl)-5-phenyl-1H-pyrazol-4-yl]acetic acid

Product 1

HCID 86626935Prop-2-yn-1-yl [3-methyl-1-(4-methylpyridin-3-yl)-5-phenyl-1H-pyrazol-4-yl]acetate

Procedure

0.445 g (6.345 mmol) of prop-2-yn-1-ol and a drop of concentrated sulfuric acid were added to 0.130 g (0.423 mmol) of [3-methyl-1-(4-methylpyridin-3-yl)-5-phenyl-1H-pyrazol-4-yl]acetic acid, and the mixture was stirred under reflux for 4 h. The solvent was removed under reduced pressure, a mixture of 10 ml of dichloromethane, 1.5 ml of diisopropylethylamine and 10 ml of water was added to the residue and the aqueous phase was extracted with 15 ml of dichloromethane. The combined organic phases were dried over sodium sulfate, and the solvent was removed under reduced pressure. Chromatography of the residue gave 0.083 g (57% of theory) of a light-beige solid of melting point 106° C.