Potassium Bromide → HCID 10584244, compound

Participants

Reaction Steps

To a solution of 5,8-dihydro-2-methoxy-5-methylnaphthalene-1,4-dione (100 mg, 490 μmol) in CHCl3 (5 mL), there was added MnO2 (213 mg, 2.45 mmol, Fluka). The stirred suspension was heated at reflux for 45 min (progress of the reaction may best be monitored by 1H NMR since TLC gives ambiguous results). The reaction was allowed to cool to rt and was filtered through a pad of Celite (the pad was washed with CHCl3 (3×3 mL)). Solvent removal yielded a yellow powder (99 mg, 100%, pure by TLC and 1H NMR); mp 138.5°-140° C.; 1H NMR δ (CDCl3) 2.76 (s, 3H), 3.88 (s, 3H), 6.11 (s, 1H), 7.54 (m, 2H), 8.07 (dd, J=1.8, 6.6 Hz, 1H); IR (KBr) 2984 (w), 2949 (w), 2927 (w), 2849 (w), 1677 (s), 1646 (s), 1619 (s), 1231 (s), 1078 (m), 1060 (m), 861 (m), 776 (m). Crystallization from MeOH yielded orange needles (mp 140°-141° C.). A 1.8 g run performed in an analogous manner yielded 1.68 g (94%) of product (>95% pure by 1H NMR with the impurity being unreacted starting material).

Provenance & Evidence