Dichloromethane → (E)-3-[2-(2-methoxycarbonylmethylenecyclohexyl)-3-oxo-2,3-dihydropyridazin-6-yl]-2-phenylpyrazolo[1,5-a]pyridine

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Reaction Steps

(E)-3-[2-(2-Carboxymethylenecyclohexyl)-3-oxo-2,3-dihydropyridazin-6-yl]-2-phenylpyrazolo[1,5-a]pyridine (36.8 mg) was suspended in dichloromethane and the mixture was cooled in an ice bath. To this was added thionyl chloride (0.1 ml). After the reaction mixture was stirred at room temperature for 4 hours, the solvent was evaporated in vacuo. The residue was dissolved in methanol (2 ml), and stirred at room temperature for 10 minutes. Methanol was evaporated in vacuo and the residue was partitioned between dichloromethane (10 ml) and saturated aqueous sodium bicarbonate. After an additional extraction with dichloromethane (10 ml), the combined extracts were washed with brine (10 ml), dried over anhydrous magnesium sulfate, and evaporated in vacuo. The oily residue was crystallized from ethyl acetate to give colorless crystals of (E)-3-[2-(2-methoxycarbonylmethylene cyclohexyl)-3-oxo-2,3-dihydropyridazin-6-yl]-2-phenylpyrazolo[1,5-a]pyridine (36.3 mg). The spectroscopic data for this compound were identical to those for the authentic sample obtained in Example 31.

Provenance & Evidence