Study On The Synthesis Of Iminostilbene With BTC

Iminostilbene (IS), english chemical name: 5H-Dibenz[b, f]azepine. Because of its high physical activity, it has been extensively studied and applied. It is an important intermediate of carbamazepine, Oxcarbazepine, and rhodium catalyst ligand. Furthermore, it can be used for the prevention and treatment of hepatitis C, and used as hemolysis-anti-drug. It is also an important raw material of genetic Engineering, materials science and other aspects.Synthetic technology of 5H-Dibenz[b, f]azepine was studied. 10,11-Dihydro-5H-dibenz[b, f]azepine as raw material was acylated by triphosgene, after bromination by bromine and dehydrobromination, reacted with sodium hydroxide in isopropanol to give 5H-Dibenz[b, f]azepine. A new amine protective group: chloroformyl group, was used to protect amine.And triphosgene(BTC) was used in acyl chlorination as green substitution for Phosgene and Diphosgene. The attracting electron effect of chlorine promoted radical substitution reaction: bromination, so that poor reaction selectivity, low conversion, many impurities, such disadvantages in old synthetic technology were solved.With 10,11-Dihydro-5H-dibenz[b, f] azepine used as raw material,and by acylation, bromination, dehydrobromination and removal of chloroformyl group, the optimal process conditions to synthesize 5H-Dibenz[b, f]azepine was: 1) Acylation: 10,11-Dihydro-5H-dibenz[b, f]azepine 58.5 g, solid triphosgene 35.6 g, Toluene 150 mL, refluxed for 10 h, cooled, pump filted and dried, 61 g solid was got. Concentrated filtrate to nearly dry, then petroleum ether 10 mL added, pump filted and dried, 10 g solid was obtained, combined with solid, the total yield was 93%. 2) Bromination and dehydrobromination: 5-chloroformyl-10,11-Dihydro-5H-dibenz[b, f]azepine 51.5 g, chlorobenzene 50 mL, heated to 90-100℃, 40 g bromine was dropped for 2 h, then heated to 130℃, after 4-5 h, 150 mL ethanol was slowly poured into, cooled,with yellow solid precipitated from solvent, pump filted and dried, 45 g yellow solid was got, yield 88%. 3) Removal of chloroformyl group: 5-chloroformyl-5H-Dibenz[b, f]azepine 25.6 g, sodium hydroxide 12 g, isopropanol 300 mL, reacted 3 h at 40℃, vacuum distilled about 200 mL isopropanol, adjusted pH to 12 with saturated sodium bicarbonate, pump filted, washed with 100 mL water, and dried to obtain the target yellow solid 13 g with yield 98.2%. The total yield was 80.4%.