(2-Methyl-2H-indazol-4-yl)methanol synthesis

Yield:1079992-60-1 90%

Reaction Conditions:

Stage #1: methyl 2-methyl-2H-indazole-4-carboxylatewith lithium aluminium tetrahydride in tetrahydrofuran at 0 - 20;Inert atmosphere;
Stage #2: with water;sodium hydroxide in tetrahydrofuran;diethyl ether;

Steps:

3

Reference Example 3 (2-methyl-2H-indazol-4-yl)methanol To a suspension of lithium aluminum hydride (14.27 g, 421 mmol) in tetrahydrofuran (315 mL) was added a solution of methyl 2-methyl-2H-indazole-4-carboxylate (40.0 g, 210 mmol) in tetrahydrofuran (106 mL) under nitrogen atmosphere at 0°C, and the mixture was stirred at room temperature for 1 hr. The reaction solution was diluted with diethyl ether at 0°C, water (15 mL), 10% aqueous sodium hydroxide solution (15 mL) and water (30 mL) were added and the mixture was stirred until gas generation stopped. The resulting precipitate was collected by filtration, and washed with ethyl acetate. The filtrate was concentrated under reduced pressure and the residue was triturated with ethyl acetate and hexane to give the title compound (30.7 g, yield 90%). ¹H-NMR (CDCl₃) δ: 1.79 (1H, t, J = 6.0 Hz), 4.23 (3H, s), 4.93 (2H, d, J = 6.0 Hz), 7.01 (1H, d, J = 6.4 Hz), 7.24 (1H, dd, J = 8.8, 6.4 Hz), 7.63 (1H, d, J = 8.8 Hz), 8.07 (1H, s).

References:

EP2141150,2010,A1 Location in patent:Page/Page column 49