4-Methylmorpholine → HCID 18996967, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 9,10-dihydro-4,5-dimethoxy-9,10-dioxoanthracene-2-carboxylic acid (2.00 g) in tetrahydrofuran (900 ml) at room temperature under nitrogen was added N-methyl morpholine (1.36 g) dropwise. The solution was then cooled to -15° C. and a solution of isobutylchloroformate (0.92 g) in tetrahydrofuran (5 ml) added during 5 minutes. The clear solution became cloudy. The mixture was stirred at -15° C. for 1 hour. To this was added portionwise over 5 minutes N-methyl O-benzylhydroxylamine hydrobromide (1.50 g). The cloudy mixture was stirred at -15° C. for 3 hours and then allowed to warm to room temperature. After 16 hours at room temperature, the mixture was filtered and the filtrate concentrated in vacuo. The resulting yellow solid was taken up in ethyl acetate (800 ml) and filtered to remove insolubles. The solution was washed with 10% aqueous sodium carbonate solution (three times), water (twice), dried (MgSO4), filtered and evaporated to yield the title compound as a bright yellow powder, m.p. 170°-171° C.

Provenance & Evidence