Morpholine → (3,4-Dinitrophenyl)(morpholino)methanone

Participants

Reaction Conditions

Reaction Steps

3,4-Dinitrobenzoic acid (1.000 Kg, 4.71 mol, 1.0 wt), tetrahydrofuran (10.00 L, 10.0 vol), and dimethylformamide (0.010 L, 0.01 vol) were charged to a flask under nitrogen. Thionyl chloride (0.450 L, 6.16 mol, 0.45 vol) was added at 20 to 30° C. and the reaction mixture was heated to 65 to 70° C. Reaction completion was determined by 1H NMR analysis (d6-DMSO), typically in 3 hours. The reaction mixture was cooled to 0 to 5° C. and triethylamine (1.25 L, 8.97 mol, 1.25 vol) was added at 0 to 10° C. Morpholine (0.62 L, 7.07 mol, 0.62 vol) was charged to the reaction mixture at 0 to 10° C. and the slurry was stirred for 30 minutes at 0 to 10° C. Reaction completion was determined by 1H NMR analysis (d6-DMSO). The reaction mixture was warmed to 15 to 20° C. and water (4.0 L, 4.0 vol) was added. This mixture was then charged to a 40 L flange flask containing water (21.00 L, 21.0 vol) at 15 to 25° C. to precipitate the product. The flask contents were cooled to and aged at 0 to 5° C. for 1 hour and the solids were collected by filtration. The filter-cake was washed with water (4×5.00 L, 4×5.0 vol) and the pH of the final wash was found to be pH 7. The wet filter-cake was analysed by 1H NMR for the presence of triethylamine hydrochloride. The filter-cake was dried at 40 to 45° C. under vacuum until the water content by KF<0.2% w/w, to yield (3,4-dinitrophenyl)-morpholin-4-yl-methanone (1.286 Kg, 97.0%, KF 0.069% w/w) as a yellow solid.

Provenance & Evidence