title: Eight 7-benzyl-3-tert-butyl-1-phenylpyrazolo[3,4-d]oxazines, encompassing structures containing no intermolecular hydrogen bonds, and hydrogen-bonded structures in one, two or three dimensions.
abstract: 7-Benzyl-3-tert-butyl-1-phenyl-6,7-dihydro-1H,4H-pyrazolo[3,4-d][1,3]oxazine, C22H25N3O, (I), and 3-tert-butyl-7-(4-methylbenzyl)-1-phenyl-6,7-dihydro-1H,4H-pyrazolo[3,4-d][1,3]oxazine, C23H27N3O, (II), are isomorphous in the space group P2(1), and molecules are linked into chains by C-H...O hydrogen bonds. In each of 3-tert-butyl-7-(4-methoxybenzyl)-1-phenyl-6,7-dihydro-1H,4H-pyrazolo[3,4-d][1,3]oxazine, C23H27N3O2, (III), which has cell dimensions rather similar to those of (I) and (II), also in P2(1), and 3-tert-butyl-1-phenyl-7-[4-(trifluoromethyl)benzyl]-6,7-dihydro-1H,4H-pyrazolo[3,4-d][1,3]oxazine, C23H24F3N3O, (IV), there are no direction-specific interactions between the molecules. In 3-tert-butyl-7-(4-nitrobenzyl)-1-phenyl-6,7-dihydro-1H,4H-pyrazolo[3,4-d][1,3]oxazine, C22H24N4O3, (V), a combination of C-H...O and C-H...N hydrogen bonds links the molecules into complex sheets. There are no direction-specific interactions between the molecules of 3-tert-butyl-7-(2,3-dimethoxybenzyl)-1-phenyl-6,7-dihydro-1H,4H-pyrazolo[3,4-d][1,3]oxazine, C24H29N3O3, (VI), but a three-dimensional framework is formed in 3-tert-butyl-7-(3,4-methylenedioxybenzyl)-1-phenyl-6,7-dihydro-1H,4H-pyrazolo[3,4-d][1,3]oxazine, C23H25N3O3, (VII), by a combination of C-H...O, C-H...N and C-H...pi(arene) hydrogen bonds, while a combination of C-H...O and C-H...pi(arene) hydrogen bonds links the molecules of 3-tert-butyl-1-phenyl-7-(3,4,5-trimethoxybenzyl)-6,7-dihydro-1H,4H-pyrazolo[3,4-d][1,3]oxazine, C25H31N3O4, (VIII), into complex sheets. In each compound, the oxazine ring adopts a half-chair conformation, while the orientations of the pendent phenyl and tert-butyl substituents relative to the pyrazolo[3,4-d]oxazine unit are all very similar.
authors: Grupo de Investigación de Compuestos Heterocíclicos, Departamento de Química, Universidad de Valle, AA 25360 Cali, Colombia.
authors: Juan C
authors: JC
authors: Castillo
authors: Rodrigo
authors: R
authors: Abonía
authors: Justo
authors: J
authors: Cobo
authors: Christopher
authors: C
authors: Glidewell
mesh_terms: D001593:Benzyl Compounds / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008958:Models, Molecular; D010078:Oxazines / Q000737:chemistry*
chemical_list: D001593:Benzyl Compounds; D010078:Oxazines