Phenylhydrazine → 7,8-Dihydro-5H-pyrido[3,2-b]azepine-6,9-dione 9-(phenylhydrazone)

Participants

Reaction Conditions

Reaction Steps

176 mg (1.0 mmol) 5H-pyrido[3,2-b]azepine-6,9(7H,8H)-dione and 162 mg (1.5 mmol) phenylhydrazine were suspended in glacial acetic acid (11 ml) and stirred for 1 hour at 70° C. After cooling to room temperature, the mixture was poured into a 5% aqueous sodium acetate solution. The mixture was extracted with 4×20 ml ethyl acetate. The combined organic layers were dried over sodium sulfate, and evaporated to dryness. Recrystallization from ethanol afforded a white solid, yield: 82 mg (32%); m.p. 206° C.; IR (KBr): 3291 cm−1 (NH), 3060/3023 cm−1 (CH-arom.), 2953/2885 cm−1 (CH-aliphat.), 1676 cm−1 (C═O); 1H-NMR (d6-DMSO, 400 MHz): δ (ppm)=2.54-2.58 (m, 2H, part of AA′XX′-system, azepine-CH2), 3.02-3.06 (m, 2H, part of AA′XX′-system, azepine-CH2), 6.76-6.81 (m, 1H, arom. H), 7.17-7.23 (m, 4H, arom. H), 7.36 (dd, 1H, 8.0/4.4 Hz, arom. H), 7.39 (dd, 1H, 8.0/1.7 Hz, arom. H), 8.40 (dd, 1H, 4.7/1.7 Hz, arom. H), 9.32 (s, 1H, NH), 9.76 (s, 1H, NH); C15H14N4O (266.31).

Provenance & Evidence