(5-METHOXYPYRIDAZIN-3-YL)METHANOL synthesis

Yield:627525-69-3 83%

Reaction Conditions:

Stage #1: 5-methoxy-pyridazine-3-carboxylic acid ethyl esterwith sodium tetrahydroborate in ethanol at 0 - 20; for 1.16667 h;
Stage #2: with hydrogenchloride;sodium hydrogencarbonate in ethanol;water at 20; pH=8;

Steps:

83; 1 EXAMPLE 83; (5-Methoxy-pyridazin-3-yl)-methanol

5-Methoxy-pyridazine-3-carboxylic acid ethyl ester (8.1 g, 44.5 mmol) was dissolved in ethanol (105 ml) under argon. The reaction mixture was cooled to 0° C. and treated with NaBH4 (3.5 g, 89 mmol). After 10 minutes, the reaction mixture was warmed to room temperature, stirred for 1 hour and treated successively with 2N HCl and saturated sodium bicarbonate to adjust the pH at 8. The solvent was removed in vacuo and the residue was stirred with MeOH (100 ml). The suspension was filtered and the filtrate was concentrated. The residue was chromatographed over silica gel (CH2Cl2 - MeOH 19 : 1) to provide (5-methoxy-pyridazin-3-yl)-methanol (5.2 g, 83%) as a light brown solid, MS: m/e=140 (M+).

References:

US2003/229096,2003,A1 Location in patent:Page 16; 6