Acetic Anhydride → HCID 14149590, compound

Participants

Reaction Steps

A mixture of 14.5 g of 2-(2-methyl-4-diethylaminophenyl)carbonylbenzoic acid (68.5 percent active). 9.0 g of 1-(2-ethoxyethyl) 2-methylindole and 60.0 ml acetic anhydride was maintained at approximately 70° C. for approximately three hours. After cooling to ambient temperature, the reaction solution was poured slowly into a mixture of toluene and 5 percent aqueous ammonium hydroxide. The toluene layer was separated and evaporated to dryness to obtain a gummy residue. The residue was triturated with hexane and the solid which separated was isolated by filtration. The solid was reslurried in 300.0 ml of hot hexane, filtered, and dried to obtain 11.5 g of 3-[1-(2-ethoxyethyl)-2-methylindol-3-yl]-3-(2-ethyl-4-diethylaminophenyl)phthalide (Formula I: R=C2H5OC2H4 ; R1 =R2 =CH3 ; R3 =R4 =C2H5 ; X=Y=H), a pale pink-colored solid which melted at 156°-158° C. Significant infrared maxima appeared at 1765 (C=O; s) and 1120 (C--O; s)cm-1. The nuclear magnetic resonance spectrum was in accord with the assigned structure. A toluene solution of the product spotted on an acidic clay or a phenolic resin developed a cyan-colored image.

Provenance & Evidence