2,5-Bis(2,5-dimethylbenzyl)terephthalic acid → 7,14-Dihydro-1,4,8,11-tetramethylpentacene-5,12-dione

Participants

Reaction Steps

To 200 mL of trifluoromethanesulfonic acid cooled to 18° C. was added slowly 53 grams of 2,5-bis(2,5-dimethylbenzyl)terephthalic acid in small portions as a solid at a rate such that the temperature remained below 25° C. The mixture was allowed to stir for 10 minutes and the cooling bath was removed. The mixture was stirred overnight at room temperature. The mixture was poured over 600 grams of ice and the resulting solid was collected by filtration. The solid was washed with 1 L of water followed by 500 mL of saturated aqueous sodium bicarbonate solution. The solid was washed with water until the pH of the filtrate was neutral to pH paper. The solid was stirred for one hour with 500 mL of tetrahydrofuran and collected by filtration. The solid was washed with tetrahydrofuran and dried to give 7,14-dihydro-1,4,8,11-tetramethylpentacene-5,12-dione.

Provenance & Evidence