Trifluoromethanesulfonic acid → 2-Chlorotetracene-5,12-dione

Participants

Reaction Conditions

Reaction Steps

A 500 mL flask was successively loaded with trifluoromethanesulfonic acid (175 mL), 3-(4-chlorobenzoyl)-naphthalene-2-carboxylic acid (Formula XV, 25.5 g), and trifluoromethanesulfonic anhydride (21 mL). The mixture was heated at 155° C. for 10 hours. The violet-blue solution was gradually poured into a 2 L beaker containing 1 L of crushed ice. Additional ice was added as necessary to keep the solution cold. The brown-green mixture was poured onto a large 25-50 μm glass frit, and the isolated solid was washed with water (1 L), methanol (300 mL), and then air-dried overnight. The crude material was purified by high vacuum train sublimation (less than 10−3 Torr) at a source temperature of 165° C. to afford 17.5 g (73 percent yield) of bright yellow product. 1H NMR (400 MHz, d6-DMSO): δ 8.89 (‘s’, 6-H and 11-H), 8.36 (m, 4 lines, J=3.2 Hz, 7-H and 10-H), 8.30 (‘d’, J=8 Hz, 4-H), 8.22 (‘d’, 2 Hz, 1-H), 8.02 (‘dd’, J=2 Hz, 4 Hz), 7.82 (m, 4 lines, J=3.2 Hz, 8-H and 9-H).

Provenance & Evidence