[C:1]1([N:7]2[C:11]([C:12]3[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=3)=[C:10]([C:18](OCC)=[O:19])[CH:9]=[N:8]2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[H-].C([Al+]CC(C)C)C(C)C.Cl>O1CCCC1>[C:1]1([N:7]2[C:11]([C:12]3[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=3)=[C:10]([CH2:18][OH:19])[CH:9]=[N:8]2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1To a mixture of ethyl 1,5-diphenyl-1H-pyrazole-4-carboxylate (14.9 g) and tetrahydrofuran (250 ml) was added dropwise diisobutylaluminum hydride (1 mol/l toluene solution, 120 ml) under ice-cooling. The reaction mixture was stirred at room temperature for 1 hr. and poured into a 1N aqueous hydrochloric acid solution. The mixture was extracted with ethyl acetate. The ethyl acetate layer was washed successively with a 1N aqueous hydrochloric acid solution and saturated brine, dried over anhydrous magnesium sulfate, and concentrated to give (1,5-diphenyl-1H-pyrazol-4-yl)methanol (12.6 g, 99%) as colorless crystals. Recrystallization thereof from ethyl acetate-hexane gave colorless prism crystals. melting point: 147-148° C.
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