Sodium Bicarbonate → 2H-1,2-Benzoxazin-3(4H)-one

Participants

Reaction Conditions

Reaction Steps

3-Oxo-6-nitro-3,4-dihydro-2H-1,4-benzoxazine. A solution of 2-amino-4-nitrophenol (8.80 g), in methyl isobutyl ketone (30 mL) was treated with sodium bicarbonate (11.5 g) and distilled water (35 mL). The mixture was cooled to 5° C. under a nitrogen atmosphere, treated dropwise with chloroacetyl chloride (5.0 mL) and then heated to reflux for 18 hours. A brown solid was collected from the cooled mixture by filtration. The solid was dried under vacuum at 50° C. for 24 hours yielding benzoxazinone (10.5 g) as a brown solid; mp 235°-236° C.; MS: m/z=195(M+1); NMR: 4.76 (s,2), 7.14 (d,1), 7.74 (d,1), 7.82 (dd,1), 11.07 (broad s,1).

Provenance & Evidence