1-Hydroxybenzotriazole hydrate → (4-(5-(3-Chloro-4-isobutylphenyl)-1,2,4-oxadiazol-3-yl)phenyl)methanol

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

N,N-Dicyclohexylcarbodiimide (1.07 g, 0.0052 mol) is added to a solution of 3-chloro-4-isobutylbenzoic acid (0.74 g, 0.0035 mol), N-hydroxy-4-hydroxymethylbenzamidine (0.867 g, 0.0052 mol) and N-hydroxybenzotriazole monohydrate (0.798 g, 0.0052 mol) in N,N-dimethylformamide (15 mL). The reaction mixture is heated at 120-125° C. for 2 hrs. It is then cooled to 0-5° C., filtered and washed with dichloromethane (2×20 mL). The filtrate is evaporated under reduced pressure and the residue is treated with demineralized water (20 mL). It is extracted with ethyl acetate (2×30 mL) and the combined extract is dried over sodium sulfate. Removal of solvent under reduced pressure gives a crude residue which is purified by column chromatography (silica gel 230-400, ethyl acetate:toluene, 15:85) to give {4-[5-(3-chloro-4-isobutylphenyl)-[1,2,4]-oxadiazol-3-yl]-phenyl}methanol.

Herkunft & Nachweise