Pyrolysis of geissovelline at 280°p roduced a white solid which had a uv spectrum corresponding to that of geissovelline and not a carbazole or a iV-acetylcarbazole. 9-Acetyl-1,2,3,4-tetrahydro-6,7-dimethoxycarbazole.-A mixture of 300 mg of 1,2,3,4-tetrahydro-6,7-dimethoxycarbazole, 0.5 g of anhydrous sodium acetate, and 3 ml of acetic anhydride was refluxed for 3 hr under nitrogen. The solvent was evaporated and the residue was distributed between chloroform and water. Evaporation of the chloroform gave 9-acetyl-l,2,3,4tetrahydro-6,7-dimethoxycarbazole, which was crystallized from ether and sublimed (0.1 mm): mp (136-137°(lit.19 mp 136°); uv max (95% EtOH) 260 nm (e 23,500), 285 (9380); proton nmr (CDCla) 1.80 (m, 4, C-2 and C-3 CH2), 2.48 (s, 3, NCOCH3), 2.52 (m, 2, C-l or C-4 CH2), 2.77 (m, 2, C-l or C-4 CH2), 3.89 (s, 6, aromatic OCH¡¡), 6.76 (s, 1, aromatic H on C-5), 7.91 (s, 1, aromatic H on C-8). 9-Acetyl-6,7-dimethoxycarbazole .-A mixture of 200 mg of 9acetyl-1,2,3,4-tetrahydro-6,7-dimethoxycarbazole and 300 mg of 30% palladium/charcoal in 5 ml of n-hexyl ether was refluxed and stirred for 3 hr under nitrogen. The mixture was filtered hot and the cooled filtrate was diluted with petroleum ether (bp 30-60°). The product crystallized slowly. Three recrystallizations from ethanol gave colorless needles of 9-acetyl-6,7-dimethoxycarbazole: mp 123-124°after drying at 80°( 0.1 mm); uv max
