Chapter 51 - Compounds with Larger Heterocyclic Rings: Seven membered Ring Compounds with an Atom from Group V of the Periodic Table in the Ring. Nitrogen

Abstract

Publisher Summary This chapter describes the methods of synthesis, structure and typical reactions of seven-membered rings containing a nitrogen atom, such as 1H-Azepines, 2H-Azepines, 4H-Azepines, dihydroazepines, tetrahydroazepines, tetrahydroazepinones, perhydroazepine (azepane, hexamethyleneimine, and azacycloheptane) and its derivatives. The study of bicyclic compounds including an azepine ring covers azepines fused to three-, four- or five-membered rings, such as homoazepines and aza-azulenes, 1-benzazepines, 2-benzazepines, and other azepines with one fused ring. Azepines with two or more annellated ring systems include dibenzazepines, such as dibenz[b,d]azepines, dibenz[b,e]azepines, dibenz[b,f]azepines, dibenz[c,e]azepines, benzpyridazepines and tribenzazepine. The seven-membered rings containing two nitrogen atoms consist of diazepines and related compounds, such as 1,2-diazepines, 1,2-diazepines with annellated benzene rings, 1,3-diazepines, 1,3-diazepines with annellated benzene rings, 1,4-diazepines, 1,4-benzodiazepines, and 1,5-benzodiazepines. 1,4-benzodiazepines have particular importance as nontoxic psychosedatives (tranquilising drugs), and seven are currently in clinical use. An important factor in the growth of interest in seven-membered heterocyclic rings has been the discovery of physiologically active compounds, characterized by greater potency and/or significantly lower addictive or narcotic effects compared with the drugs they replaced. In the case of seven-membered rings containing three or more nitrogen atoms, four triazepine ring systems are possible, and derivatives of each system are known, but no monocyclic 1,2,3-triazepines have been prepared.