2,5-Bis(4-methylphenyl)-7-phenyl-6,7-dihydropyrazolo[1,5-a]pyrimidine-3,6-dicarbaldehyde: hydrogen-bonded sheets built from N—H...O and C—H...O hydrogen bonds (original) (raw)
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Acta crystallographica. Section C, Crystal structure communications, 2005
5-methyl-2-(4-methylphenyl)-7,8-dihydro-6H-cyclopenta[g]pyrazolo[1,5-a]pyrimidine, C17H17N3, 2-(4-chlorophenyl)-5-methyl-7,8-dihydro-6H-cyclopenta[g]pyrazolo[1,5-a]pyrimidine, C16H14ClN3, and 2-(4-bromophenyl)-5-methyl-7,8-dihydro-6H-cyclopenta[g]pyrazolo[1,5-a]pyrimidine, C16H14BrN3, are isostructural; in each compound, the molecules are linked into chains by a single C-H...pi(arene) hydrogen bond. Molecules of 2-(4-methoxyphenyl)-5-methyl-7,8-dihydro-6H-cyclopenta[g]pyrazolo[1,5-a]pyrimidine, C17H17N3O, are linked by a single C-H...N hydrogen bond into chains, which are themselves linked into sheets by a pi-pi stacking interaction.
Acta Crystallographica Section C Crystal Structure Communications, 2006
Molecules of the title compound, C 27 H 23 ClN 2 O 2 , are linked into sheets of alternating large and small rings by a combination of CÐHÁ Á ÁO and CÐHÁ Á Á%(arene) hydrogen bonds. Comment The title compound, (I), has been obtained from the basecatalysed condensation of 5-chloro-3-methyl-1-phenylpyrazole-4-carbaldehyde with acetophenone. Evidently, the intended target 3-(5-chloro-3-methyl-1-phenylpyrazol-4-yl)-1phenylpropenone, (II), required as an intermediate for the synthesis of novel fused heterocyclic systems, has undergone a Michael-type reaction with a further molecule of acetophenone to form the observed product, (I). Compound (I) and the analogous 3-(5-chloro-3-methyl-1phenylpyrazol-4-yl)-1,5-di-2-thienylpentane-1,5-dione, (III) (Trilleras et al., 2005), both crystallize in the space group Pbca, with dimensions which are fairly similar, bearing in mind the different temperatures for the two determinations [293 (2) K for (I) and 120 (2) K for (III)], and hence the two compounds are isomorphous. In addition, the corresponding atom coordinates are very similar, as are the molecular conformations, with an all-trans and nearly planar aliphatic chain exhibiting approximate local mirror symmetry (Table 1). Indeed, with the exception of the N-bound phenyl ring (C11±C16), which makes a dihedral angle of 42.7 (2) with the pyrazole ring, the entire molecule has approximate mirror symmetry. However, there are some signi®cant differences between the supramolecular structures of (I) and (III), so that these compounds are not strictly isostructural.
Acta crystallographica. Section C, Crystal structure communications, 2006
A hydrogen-bonded chain of rings in 7-amino-5-tert-butyl-2-methylpyrazolo[1,5-a]pyrimidine, and a hydrogen-bonded framework structure in 3,7-diamino-2,5-dimethylpyrazolo[1,5-a]pyrimidine monohydrate
Acta Crystallographica Section E Structure Reports Online, 2006
The molecules of the title compound, C 27 H 21 N 3 O 2 , contain an intramolecular O-HÁ Á ÁO hydrogen bond, and they are linked into complex sheets by a combination of two C-HÁ Á ÁN hydrogen bonds and two C-HÁ Á ÁO hydrogen bonds. Comment We report here the structure of the title new pyrazolo[1,5a]pyrimidine, (I) (Fig. 1), prepared under solvent-free conditions from the reaction between a 5-aminopyrazole and a 2benzoylchromone. organic papers Acta Cryst. (2006). E62, o3195-o3197 Portilla et al. C 27 H 21 N 3 O 2 o3197