Acetic Anhydride → HCID 15918697, compound

Participants

Reaction Steps

A mixture of 6.3 g of 2-(4-dimethylaminophenyl)carbonyl-5-dimethylaminobenzoic acid and 150.0 ml of acetic anhydride was stirred for approximately fifteen minutes at ambient temperature. Slowly, 10.0 ml of piperidine and 10.0 ml of methyl alcohol were added to the mixture. Two grams of potassium hydroxide was added to complete the solution. The temperature rose to 55° C. with the addition of the potassium hydroxide. The resulting solution was allowed to stir overnight with gradual return to ambient temperature. Slowly, this solution was poured into a mixture of five percent aqueous ammonium hydroxide and toluene. After separation, the toluene layer was washed first with water and then with saturated aqueous sodium chloride solution. The resulting toluene layer was evaporated to dryness. The residue was slurried in 100.0 ml of isopropyl alcohol and the separated solid was collected by filtration, washed three times, each with 30.0 ml of isopropyl alcohol, and dried to obtain 4.0 g of 3-methoxy-3-(4-dimethylaminophenyl)-6-dimethylaminophthalide (Formula II: R0 =R=R2 =R5 =H; R1 =N(CH3)2 ; R4 =R4' =Y=CH3 ; X=O), a pale green solid which melted at 150° to 153° C. A significant infrared maximum appeared at 1765 cm-1 (C=O;s). The nuclear magnetic resonance spectrum was in accord with the assigned structure. A toluene solution of the product spotted on an acidic clay-coated paper developed a green-colored image.

Provenance & Evidence