18-Crown-6 → 3-[2-{3-(Tert-butyldimethylsilyloxy)cyclohexyl}-3-oxo-2,3-dihydropyridazin-6-yl]-2-phenylpyrazolo[1,5-a]pyridine

Participants

Reaction Steps

A solution of 3- (3-oxo-2, 3-dihydropyridazin-6-yl)-2-phenylpyrazolo[1,5-a]pyridine (870 mg), 1- (tert-butyldimethylsilyl)oxy-3-iodocyclohexane (1.5 g), potassium tert-butoxide (472 mg) and 18-crown-6 (80 mg) in 15 N,N-dimethylformamide (10 ml) was stirred for 2 hours at room temperature. A reaction mixture was diluted with a mixture of ethyl acetate (150 ml) and n-hexane (50 ml), which was washed in turn with water (50 ml), 1N-aqueous sodium hydroxide solution (50 ml×3) and saturated sodium chloride in water (50 ml×2), and dried over magnesium sulfate. Evaporation of the solvent gave a residue, which was chromatographed on silica gel (80 ml) eluting in turn with 25%, 33% and 50% ethyl acetate in dichloromethane to give 3-[2-{3-(tert-butyldimethylsilyloxy)cyclohexyl}-3-oxo-2,3-dihydropyridazin-6-yl]-2-phenylpyrazolo[1, 5-a]-pyridine (0.23 g).

Provenance & Evidence