Toluene → 1-Benzyloxymethyl-1,5-dihydropyrrolo[2,3-d]pyridazin-4-one

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Reaction Steps

To 33.4 g (100 mmol) of 1-benzyloxymethyl-2-bromo-1,5-dihydropyrrolo[2,3-d]pyridazin-4-one obtained in Reference example 17-(d) were added 4.5 g of 5% palladium-active carbon, 330 ml of toluene, 330 ml of tetrahydrofuran and 21 ml (121 mmol) of N,N-diisopropylethylamine, and the mixture was stirred under 1 atm hydrogen atmosphere at 60° C. for 1 hour. After completion of the reaction, the insoluble material in the reaction suspension was removed by filtration, followed by washing with 300 ml of a mixed solution (chloroform/methanol=1/1 (V/V)), and the filtrate and the washing solution were combined, then concentrated under reduced pressure. To the obtained concentrate was added 400 ml of water, and the mixture was extracted with a mixed solvent comprising 500 ml of chloroform and 30 ml of ethanol. The organic layer after separation was washed successively with water and a saturated aqueous solution of sodium chloride, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to obtain 24.3 g of the title compound as a yellowish brown solid. (Yield: 95%)

Provenance & Evidence