Benzyl Alcohol → (+)-4,5-dihydro-3-phenyl-1H-pyrazole-5-carboxylic acid, phenylmethyl ester, hydrochloride

Reaction equation

[C:1]1([C:7]2[CH2:11][CH:10]([C:12]([OH:14])=[O:13])[NH:9][N:8]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.S(Cl)([Cl:17])=O.[CH2:19](O)[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1>>[ClH:17].[C:1]1([C:7]2[CH2:11][CH:10]([C:12]([O:14][CH2:19][C:20]3[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=3)=[O:13])[NH:9][N:8]=2)[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

Reactant 3

HCID 244Benzyl Alcohol2×

HCID 24386Thionyl Chloride2×

HCID 131023953-Phenyl-4,5-dihydro-1H-pyrazole-5-carboxylic acid

Product 1

HCID 131712948(+)-4,5-dihydro-3-phenyl-1H-pyrazole-5-carboxylic acid, phenylmethyl ester, hydrochloride

Procedure

20 g. of (+)-4,5-Dihydro-3-phenyl-1H-pyrazole-5-carboxylic acid is added at room temperature to a solution of 25 g. of thionyl chloride in 150 ml. of benzyl alcohol (prepared by adding the thionyl chloride to the benzyl alcohol at -5°) and allowed to stir for 48 hours. Hydrochloric acid is removed in vacuo and the remaining solution is poured into 250 ml. of anhydrous ether. The separated product is collected, washed with fresh ether, and dried to give (+)-4,5-dihydro-3-phenyl-1H-pyrazole-5-carboxylic acid, phenylmethyl ester, hydrochloride (1:1).