Hydrazine hydrate (1:1) → HCID 59651895, compound

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Reaction Steps

A mixture of 4-[4-(3-ethoxycarbonyl-propionyl)-2,6-difluoro-phenoxy]-piperidine-1-carboxylic acid tert-butyl ester (3.21 g, 7.27 mmol) and hydrazine monohydrate (0.7 mL, 14.1 mmol) in isopropanol (20 mL) was stirred at reflux overnight. Isopropanol was concentrated at reduced pressure and partitioned between saturated aqueous sodium bicarbonate solution and methylene chloride. The aqueous layer was extracted twice with methylene chloride and the combined organics was washed with brine, dried (Na2SO4), filtered, and concentrated to provide a crude material. The crude material was purified by ISCO (80 g silica gel column) chromatography using 15 to 60% EtOAc in hexane to obtain 4-[2,6-difluoro-4-(6-oxo-1,4,5,6-tetrahydro-pyridazin-3-yl)-phenoxy]-piperidine-1-carboxylic acid tert-butyl ester (0.42 g, 14%).

Provenance & Evidence