Hydrochloric Acid → 3-Chloro-2-(3-cyclopropoxy-4-difluoromethoxyphenyl)-1,5-dihydropyrrolo[2,3-d]pyridazin-4-one

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Reaction Conditions

Reaction Steps

To 311 mg (0.624 mmol) of 3-chloro-2-(3-cyclopropoxy-4-difluoromethoxyphenyl)-1-(2-trimethylsilylethoxymethyl)-1,5-dihydropyrrolo[2,3-d]pyridazin-4-one obtained in Example 2-(a) was added 15 ml of 1,4-dioxane solution containing 4N hydrogen chloride, and the mixture was stirred at 40° C. for 28 hours. After completion of the reaction, the reaction suspension was cooled by allowing to stand, and precipitated solid was collected by filtration and washed with diisopropyl ether. To the obtained solid were added 22 ml of methanol and 1.5 ml of 28% aqueous ammonia, and the mixture was stirred under room temperature for 3 hours. Then, the solution was concentrated under reduced pressure, diisopropyl ether and hexane were added to the obtained solid, a treatment with ultrasonic wave was carried out, and precipitated solid was collected by filtration. The obtained solid was washed with diisopropyl ether and dried under reduced pressure to obtain 177 mg of the title compound as a white solid. (Yield: 77%)

Provenance & Evidence