Eight 7-benzyl-3-tert-butyl-1-phenyl-pyrazolo[3,4-d]oxazines, encompassing structures containing no inter-molecular 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-methyl-benz-yl)-1-phenyl-6,7-dihydro-1H,4H-pyrazolo[3,4-d][1, 3]oxazine, C23H27N3O, (II), are isomorphous in the space group P21, and mol-ecules are linked into chains by C- H⋯O hydrogen bonds. In each of 3-tert-butyl-7-(4-methoxy-benz-yl)-1- phenyl-6,7-dihydro-1H,4H-pyrazolo[3,4-d][1,3]oxazine, C23H 27N3O2, (III), which has cell dimensions rather similar to those of (I) and (II), also in P21, and 3-tert-butyl-1-phenyl-7-[4-(trifluoro-meth-yl)benz-yl]-6,7-dihydro-1H, 4H-pyrazolo[3,4-d][1,3]oxazine, C23H24F3N 3O, (IV), there are no direction-specific inter-actions between the mol-ecules. In 3-tert-butyl-7-(4-nitro-benz-yl)-1-phenyl-6,7-dihydro-1H,4H- pyrazolo[3,4-d][1,3]oxazine, C22H24N4O 3, (V), a combination of C- H⋯O and C- H⋯N hydrogen bonds links the mol-ecules into complex sheets. There are no direction-specific inter-actions between the mol-ecules of 3-tert-butyl-7-(2,3-dimethoxy-benz-yl)- 1-phenyl-6,7-dihydro-1H,4H-pyrazolo[3,4-d][1,3]oxazine, C24H 29N3O3, (VI), but a three-dimensional framework is formed in 3-tert-butyl-7-(3,4-methyl-enedioxy-benz-yl)-1-phenyl-6,7-dihydro- 1H,4H-pyrazolo[3,4-d][1,3]oxazine, C23H25N 3O3, (VII), by a combination of C- H⋯O, C- H⋯N and C- H⋯π(arene) hydrogen bonds, while a combination of C- H⋯O and C- H⋯π(arene) hydrogen bonds links the mol-ecules of 3-tert-butyl-1-phenyl-7-(3,4,5-trimethoxy-benz-yl)-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. © 2009 International Union of Crystallography.