Ethyl Acetate → 3-[2-{2-(N-carboxymethyl-N-methylcarbamoyl)methyl-1-cyclohexenyl}-3-oxo-2,3-dihydropyridazin-6-yl]-2-phenylpyrazolo[1,5-a]pyridine

Participants

Reaction Steps

To a solution of 3-[2-{2-(N-ethoxycarbonylmethyl-N-methylcarbamoyl)methyl-1-cyclohexenyl}-3-oxo-2,3-dihydropyridazin-6-yl]-2-phenylpyrazolo[1,5-a]pyridine (710 mg) in a mixture of dioxane (7 ml) and water (4 ml) was added 1N-aqueous sodium hydroxide solution (3.4 ml), which was stirred for two hours at room temperature. The reaction mixture was poured into ethyl acetate (100 ml) and aqueous layer was collected, which was adjusted to pH 1.5 with 6N-aqueous hydrochloric acid and extracted with ethyl acetate (100 ml×2). Organic layers were combined, washed in turn with water (50 ml×3) and brine (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 dichloromethane, 5%, 10%, 15% methanol in dichloromethane. Fractions containing desired product were collected. Evaporation of the solvent gave a residue, which was recrystallized from a mixture of dichloromethane and n-hexane to give 3-[2-{2-(N-carboxymethyl-N-methylcarbamoyl)methyl-1-cyclohexenyl}-3-oxo-2,3-dihydropyridazin-6-yl]-2-phenylpyrazolo[1,5-a]pyridine (300 mg).

Provenance & Evidence