4-Methylmorpholine → 8-bromo-6-(morpholine-4-carbonyl)-2-morpholino-4H-chromen-4-one

Participants

Reaction Conditions

Reaction Steps

KOH (0.419 L, 4889 mmol) was added portionwise to methyl 8-bromo-2-morpholino-4-oxo-4H-chromene-6-carboxylate (900 g, 2444 mmol) in water (5 L) at 20° C. over a period of 1 hour. The resulting suspension was stirred at 20° C. for 4 hours until saponification was complete. The reaction was filtered to remove insoluble particles and transferred into a vessel containing water (2 L) (vessel 1). Morpholine (0.639 L, 7333 mmol) was added and agitation continued. 2-chloro-4,6-dimethoxy-1,3,5-triazine (1931 g, 11000 mmol) and water (8 L) was charged to vessel 2 and the temperature adjusted to approximately 7° C., 4-methylmorpholine (134 mL, 1222 mmol) was charged at a rate to maintain the contents at 10° C. and the contents agitated for 4 hours. The contents of vessel 2 was transferred to vessel 1 and agitated at room temperature overnight. DCM (5 L) was then added and the mixture transferred to a 30 litre separator, extracted with a further portion of DCM and the organic extracts combined, dried (Na2SO4) and evaporated to dryness. The solid was stirred in ethyl acetate and filtered to give 8-bromo-6-(morpholine-4-carbonyl)-2-morpholino-4H-chromen-4-one (520 g, 50.3%) as a slightly grey solid. Mass Spectrum: m/z [M+H]+=425.

Provenance & Evidence