Hydrochloric Acid → methyl 2-((R)-2-methylmorpholino)-4-oxo-8-(pyrrolidin-2-yl)-4H-chromene-6-carboxylate

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Reaction Steps

HCl 4N (6.24 mL, 24.97 mmol) was added to a stirred solution of tert-butyl 2-(6-(methoxycarbonyl)-2-((R)-2-methylmorpholino)-4-oxo-4H-chromen-8-yl)pyrrolidine-1-carboxylate (1.18 g, 2.50 mmol) in DCM (10 mL) at room temperature and stirred for 16 h. the solvents were evaporated and DCM (5 mL) and MeOH (5 mL) were added followed by 10% methanolic ammonia (7 N) in dichloromethane (5 mL). The solid was filtered and washed with a 1:1 mixture of DCM and MeOH. The solvent was evaporated to dryness and the crude product was purified by flash chromatography on silica gel eluting with 0 to 10% MeOH in DCM. The solvent was evaporated to dryness, triturated with diethyl ether to give a solid which was collected by filtration and dried under vacuum to give methyl 2-((R)-2-methylmorpholino)-4-oxo-8-(pyrrolidin-2-yl)-4H-chromene-6-carboxylate (0.760 g, 82%) as a white solid. Mass Spectrum: m/z [M+H]=373.

Provenance & Evidence