Diisobutylaluminum hydride → (1-(4-fluorophenyl)-6-methyl-1H-indazol-5-yl)methanol

Participants

Reaction Steps

A solution of methyl 1-(4-fluorophenyl)-6-methyl-1H-indazole-5-carboxylate (1.52 g, 5.35 mmol) and THF (36 mL) was cooled to about 0° C. and to it was added DIBAL-H (1 M solution in toluene, 11.2 mL, 11.2 mmol) and stirred for about 2 h. To the reaction mixture was added DIBAL-H (1 M solution in toluene, 6.0 mL, 6.0 mmol) and stirring was continued for 2 h. The reaction was quenched with EtOAc (˜20 mL) and allowed to warm to ambient temperature. To the reaction mixture was added 10% aqueous Rochelle's salt (40 mL) and stirred for about 16 h. The reaction mixture was partially concentrated under reduced pressure and partitioned between EtOAc (60 mL) and water (20 mL). The aqueous layer was back extracted with EtOAc (30 mL). The combined organic layers were dried over MgSO4, filtered and concentrated under reduced pressure. The residue was purified by column chromatography (SiO2, DCM/MeOH 100:0 to 0:10) to afford (1-(4-fluorophenyl)-6-methyl-1H-indazol-5-yl)methanol (1.14 g, 4.45 mmol, 83%). LC-MS (Table 1, Method g) Rt=2.01 min, m/z 257 (M+H)+.

Provenance & Evidence