Trifluoroacetic acid → 3,9-Dimethylpentacene-5,7(12H,14H)-dione

Reaction equation

[CH3:1][C:2]1[CH:28]=[CH:27][C:5]([CH2:6][C:7]2[CH:15]=[C:14]([CH2:16][C:17]3[CH:22]=[CH:21][C:20]([CH3:23])=[CH:19][CH:18]=3)[C:10]([C:11](O)=[O:12])=[CH:9][C:8]=2[C:24]([OH:26])=O)=[CH:4][CH:3]=1.FC(F)(F)C(O)=O.FC(F)(F)S(O)(=O)=O>>[CH3:23][C:20]1[CH:21]=[CH:22][C:17]2[CH2:16][C:14]3[C:10]([C:11](=[O:12])[C:18]=2[CH:19]=1)=[CH:9][C:8]1[C:24](=[O:26])[C:27]2[C:5](=[CH:4][CH:3]=[C:2]([CH3:1])[CH:28]=2)[CH2:6][C:7]=1[CH:15]=3

Participants

Reactant 3

HCID 6422Trifluoroacetic acid

HCID 62406Trifluoromethanesulfonic acid

HCID 22269445HCID 22269445, compound

Product 1

HCID 222694733,9-Dimethylpentacene-5,7(12H,14H)-dione

Procedure

To 14.1 grams of 4,6-bis(4-methylbenzyl)isophthalic acid was added 75 mL of trifluoroacetic acid followed by 48 grams of trifluoromethanesulfonic acid. After stirring for 3 days at room temperature, the mixture was poured over 200 g of ice, and the resulting solid was collected by filtration. The solid was washed with 400 mL of saturated aqueous sodium bicarbonate solution, followed by 1100 mL of water until the filtrate was neutral to pH paper. The solid was washed with heptane and dried to give 3,9-dimethylpentacene-5,7(12H,14H)-dione.