Diisobutylaluminumhydride → methyl 2-bromo-3-(2-butyn-1-yl)-5-formyl-3H-imidazole-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

45 ml diisobutylaluminum hydride solution (1M in toluene) are added dropwise to 12.45 g dimethyl 2-bromo-3-(2-butyn-1-yl)-1H-imidazole-4,5-dicarboxylate in 150 ml of tetrahydrofuran under an argon atmosphere at −65° C. The reaction mixture is stirred for two hours at −65° C., then another 9 ml diisobutylaluminum hydride solution are added. After another hour the reaction mixture is quenched at −65° C. with a mixture of 1 M hydrochloric acid and tetrahydrofuran (1:1) and stirred for ten minutes. Then the cooling bath is removed, the reaction mixture is diluted with water and extracted with ethyl acetate. The combined organic phases are dried over magnesium sulphate and evaporated down. The crude product is purified by chromatography over a silica gel column with cyclohexane/ethyl acetate (2:1 to 1:1).

Provenance & Evidence