Acetic Anhydride → 5-Methylcarbonyloxy-9-diethylamino-12-acetylbenzo[a]phenoxazine

Participants

Reaction Conditions

Reaction Steps

A mixture of 10.0 g of 9-diethylaminobenzo[a]phenoxazin-5-one, 75.0 ml of acetic anhydride and 10.0 g of zinc dust was maintained at approximately 80° C. for approximately thirty minutes. After the reaction mixture was cooled to room temperature, the solid present was collected by filtration and it was washed twice, each time with 25.0 ml of acetone. The filtrate and the acetone washes were combined and added slowly to approximately 400.0 ml of water. An oily liquid separated from the water and was extracted from the water with toluene. Subsequently, the toluene solution was washed with water and saturated sodium chloride solution, treated with activated carbon and clarified. The resulting toluene solution was evaporated to dryness. The residue obtained was dissolved in a mixture of ethyl acetate:toluene (2:23::V:V) and purified by passing the solution through a chromatography column packed with silica gel. Fractions 7 through 11 were combined, evaporated to dryness and the residue triturated with hexane to obtain 0.26 g of 5-methylcarbonyloxy-9-diethylamino-12-acetylbenzo[a]phenoxazine (Formula III: R=CH3 ; R2 =R3 =C2H5), a pale brown-colored solid which melted at 64° to 72° C. Significant infrared maxima appeared at 1772 cm-1 (C=O;m) and 1680 cm-1 (C=O;s). Paper treated with an ink formulation of the product produced a strong purple-colored image when traced with an applied voltage stylus.

Provenance & Evidence