title: Six polycyclic pyrimidoazepine derivatives: syntheses, molecular structures and supramolecular assembly.
abstract: A versatile synthetic method has been developed for the formation of variously substituted polycyclic pyrimidoazepine derivatives, formed by nucleophilic substitution reactions on the corresponding chloro-substituted compounds; the reactions can be promoted either by conventional heating in basic solutions or by microwave heating in solvent-free systems. Thus, (6RS)-6,11-dimethyl-3,5,6,11-tetrahydro-4H-benzo[b]pyrimido[5,4-f]azepin-4-one, C14H15N3O, (I), was isolated from a solution containing (6RS)-4-chloro-8-hydroxy-6,11-dimethyl-6,11-dihydro-5H-benzo[b]pyrimido[5,4-f]azepine and benzene-1,2-diamine; (6RS)-4-butoxy-6,11-dimethyl-6,11-dihydro-5H-benzo[b]pyrimido[5,4-f]azepin-8-ol, C18H23N3O2, (II), was formed by reaction of the corresponding 6-chloro compound with butanol, and (RS)-4-dimethylamino-6,11-dimethyl-6,11-dihydro-5H-benzo[b]pyrimido[5,4-f]azepin-8-ol, C16H20N4O, (III), was formed by reaction of the chloro analogue with alkaline dimethylformamide. (6RS)-N-Benzyl-8-methoxy-6,11-dimethyl-6,11-dihydro-5H-benzo[b]pyrimido[5,4-f]azepin-4-amine, C22H24N4O, (IV), (6RS)-N-benzyl-6-methyl-1,2,6,7-tetrahydropyrimido[5',4':6,7]azepino[3,2,1-hi]indol-8-amine, C22H22N4, (V), and (7RS)-N-benzyl-7-methyl-2,3,7,8-tetrahydro-1H-pyrimido[5',4':6,7]azepino[3,2,1-ij]quinolin-9-amine, C23H24N4, (VI), were all formed by reaction of the corresponding chloro compounds with benzylamine under microwave irradiation. In each of compounds (I)-(IV) and (VI), the azepine ring adopts a conformation close to the boat form, with the C-methyl group in a quasi-equatorial site, whereas the corresponding ring in (V) adopts a conformation intermediate between the twist-boat and twist-chair forms, with the C-methyl group in a quasi-axial site. No two of the structures of (I)-(VI) exhibit the same range of intermolecular hydrogen bonds: different types of sheet are formed in each of (I), (II), (V) and (VI), and different types of chain in each of (III) and (IV).
authors.affiliation: Laboratorio de Síntesis Orgánico, Escuela de Química, Universidad Industrial de Santander, AA 678 Bucaaramanga, Colombia.
authors.forename: Lina M
authors.initials: LM
authors.lastname: Acosta Quintero
authors.affiliation: Laboratorio de Síntesis Orgánico, Escuela de Química, Universidad Industrial de Santander, AA 678 Bucaaramanga, Colombia.
authors.forename: Alirio
authors.initials: A
authors.lastname: Palma
authors.affiliation: Departamento de Química Inorgánica y Orgánica, Universidad de Jaén, 23071 Jaén, Spain.
authors.forename: Justo
authors.initials: J
authors.lastname: Cobo
authors.affiliation: School of Chemistry, University of St Andrews, Fife KY16 9ST, Scotland.
authors.forename: Christopher
authors.initials: C
authors.lastname: Glidewell
mesh_terms: D001381:Azepines / Q000138:chemical synthesis* / Q000737:chemistry; D018360:Crystallography, X-Ray; D003959:Diamines / Q000737:chemistry; D006860:Hydrogen Bonding; D008958:Models, Molecular; D015394:Molecular Structure; D011083:Polycyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D001381:Azepines; D003959:Diamines; D011083:Polycyclic Compounds
keywords: crystal structure; fused-ring systems; hydrogen bonding; molecular conformation; molecular structure; nucleophilic substitution; pharmaceutical chemistry; pyrimidoazepines; synthesis