Sodium borohydride → 1-[2-(alpha-hydroxybenzyl)-4-chlorophenyl]-5-[(dimethylamino)-methyl]-1H-1,2,4-triazole-3-methanol

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Reaction Steps

9.1 g (0.24 mole) of sodium borohydride is added portionwise at room temperature, with stirring, to a solution of 16.0 g (0.040 mole) of 1-(2-benzoyl-4-chlorophenyl)-5-[(dimethylamino)-methyl]-1H-1,2,4-triazole-3-carboxylic acid methyl ester [see Example 2] in 320 ml of tetrahydrofuran and 320 ml of methanol. The temperature of the reaction solution rises during the addition to 40°. The reaction mixture is subsequently heated for one hour at 50°; 100 ml of ice water is then added, and the bulk of the tetrahydrofuran and of the methanol is evaporated off in vacuo. The aqueous residue is extracted twice with ethyl acetate. The organic phase is washed once with 1 N sodium hydroxide solution, and is then extracted three times with 2 N hydrochloric acid solution. Sodium carbonate is added to the aqueous acidified extracts until the pH-value reaches 10. The precipitated base is dissolved in ethyl acetate; the solution is washed twice with water and once with saturated sodium chloride solution; it is dried over sodium sulphate and concentrated in vacuo. The residue is triturated with ether and hexane, whereupon the reaction product precipitates in crystalline form. After filtration with suction and drying in vacuum, there is obtained 1-[2-(α-hydroxybenzyl)-4-chlorophenyl]-5-[(dimethylamino)-methyl]-1H-1,2,4-triazole-3-methanol, m.p. 121°-123°.

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