Hydrochloric Acid → HCID 117701571, compound

Participants

Reaction Steps

To a solution of 7-(benzyloxy)-N-(2-hydroxyethyl)-3-methyl-4-oxo-2-(1-propanoylpiperidin-4-yl)-4H-chromene-8-carboxamide (140 mg, 0.28 mmol) obtained in Example 35-2 in dichloromethane (4 mL), thionyl chloride (62 μL, 0.85 mmol) was added dropwise, and then the mixture was stirred at room temperature for 10 hours. The reaction solution was concentrated under reduced pressure, and then the residue was subjected to azeotropy with toluene (6 mL). 1,2-Dichloroethane (4 mL) and 1,8-diazabicyclo[5.4.0]undec-7-ene (950 μL, 5.68 mmol) were added to the obtained residue, and then the mixture was heated to reflux for 4 days. A 0.2 N aqueous hydrochloric acid solution (50 mL) was added to the reaction solution, followed by extraction with dichloromethane. The organic layer was dried over sodium sulfate. The desiccant was filtered off, and then the filtrate was concentrated under reduced pressure. The obtained residue was purified by NH silica gel column chromatography (n-hexane/ethyl acetate=90/10→60/40) to obtain 37 mg of the title compound (yield: 27%) as an oil.

Provenance & Evidence