[3-(hydroxyMethyl)-1-Methyl-pyrazol-4-yl]Methanol synthesis

Yield:1056039-91-8 87%

Reaction Conditions:

Stage #1: 1-methyl-3,4-dimethoxycarbonylpyrazolewith lithium aluminium tetrahydride in diethyl ether;dichloromethane; for 24 h;Heating / reflux;
Stage #2: with methanol in diethyl ether;dichloromethane;

Steps:

5.3

The solution of dimethyl 1 -methyl- 1 H-pyrazole-3,4-dicarboxylate (4.0 g, 20 mmol) in anhydrous ether (10 mL) and anhydrous DCM (60 mL) was added slowly to a stirred suspension Of LiAlH₄ (1.4 g, 37 mmol) in anhydrous ether (60 mL), and the mixture was reflux for 24 h. The solution was quenched by careful addition of MeOH, and the solvents were removed on a rotavap. DCM and MeOH were added to dissolve the mixture. The solutionn was filtered off, and the filtrate evaporated in vacuo. Crude (1 -methyl- IH- pyrazole-3,4-diyl)dimethanol was purified by silica gel column chromatography (DCM : MeOH = 20:1). Yield 2.5 g, 87%.

References:

WO2008/108988,2008,A1 Location in patent:Page/Page column 58