Acta Crystallographica Section B

Structural Science

Volume 64, Part 5 (October 2008)

research papers

Acta Cryst. (2008). B64, 610-622 [ doi:10.1107/S0108768108019903 ]

Anhydrous versus hydrated N⁴-substituted 1H-pyrazolo[3,4-d]pyrimidine-4,6-diamines: hydrogen bonding in two and three dimensions

J. Trilleras, J. Quiroga, J. Cobo, A. Marchal, M. Nogueras, J. N. Low and C. Glidewell

Abstract: Ten new N⁴-substituted 1H-pyrazolo[3,4-d]pyrimidine-4,6-diamines have been synthesized and the structures of nine of them are reported here, falling into two clear groups, those which are stoichiometric hydrates and those which crystallize in solvent-free forms. In each of N⁴-methyl-N⁴-phenyl-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine, C₁₂H₁₂N₆ (I), N⁴-cyclohexyl-N⁴-methyl-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine, C₁₂H₁₈N₆ (II), and N⁴-(3-chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine, C₁₁H₉ClN₆ (III), the molecules are linked into hydrogen-bonded sheets. The molecules of 2-{4-(6-amino-1H-pyrazolo[3,4-d]pyrimidin-4-yl)piperazin-1-yl}ethanol, C₁₁H₁₇N₇O (IV), are linked into a three-dimensional framework, while the structure of N⁴-methyl-N⁴-(4-methylphenyl)-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine monohydrate, C₁₃H₁₄N₆·H₂O (V), is only two-dimensional despite the presence of five independent hydrogen bonds. The stoichiometric hemihydrates N⁴-ethyl-N⁴-phenyl-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine hemihydrate, C₁₃H₁₄N₆·0.5H₂O (VI) and N⁴-(4-methoxyphenyl)-N⁴-methyl-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine hemihydrate, C₁₃H₁₄N₆O·0.5H₂O (VII), exhibit remarkably similar sheet structures, despite different space groups and Z' values, Z' = 0.5 in C2/c for (VI) and Z' = 1 in $P\bar 1$ for (VII). N⁴-4-Benzyl-N⁴-phenyl-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine monohydrate, C₁₈H₁₆N₆·H₂O (VIII), crystallizes with Z' = 2 in P2₁/n, and the four independent molecular components are linked into sheets by a total of 11 intermolecular hydrogen bonds. The sheet structure in {4-(pyrrolidin-1-yl)-1H-pyrazolo[3,4-d]pyrimidine-6-amine} ethanol hemisolvate hemihydrate, C₉H₁₂N₆·0.5C₂H₆O·0.5H₂O (IX), is built from the pyrimidine and water components only; it contains eight independent hydrogen bonds, and it very closely mimics the sheets in (VI) and (VII); the ethanol molecules are pendent from these sheets. The N⁴-alkyl-N⁴-aryl-4-aminopyrazolopyrimidine molecules in (I), (V)-(VIII) all adopt very similar conformations, dominated in each case by an intramolecular C-H [pi] (arene) hydrogen bond: this interaction is absent from (III) where the molecular conformation is entirely different and probably dominated by the intermolecular hydrogen bonds.

Keywords: hydrogen bonding; stoichiometric hydrates; biochemical reactions.


	Structure factor file (CIF format) (134.0 kbytes) [ doi:10.1107/S0108768108019903/bm5056Isup2.fcf ] Contains datablock I

	Structure factor file (CIF format) (144.5 kbytes) [ doi:10.1107/S0108768108019903/bm5056IIsup3.fcf ] Contains datablock II

	Structure factor file (CIF format) (126.1 kbytes) [ doi:10.1107/S0108768108019903/bm5056IIIsup4.fcf ] Contains datablock III

	Structure factor file (CIF format) (144.2 kbytes) [ doi:10.1107/S0108768108019903/bm5056IVsup5.fcf ] Contains datablock IV

	Structure factor file (CIF format) (152.6 kbytes) [ doi:10.1107/S0108768108019903/bm5056Vsup6.fcf ] Contains datablock V

	Structure factor file (CIF format) (149.7 kbytes) [ doi:10.1107/S0108768108019903/bm5056VIsup7.fcf ] Contains datablock VI

	Structure factor file (CIF format) (315.3 kbytes) [ doi:10.1107/S0108768108019903/bm5056VIIsup8.fcf ] Contains datablock VII

	Structure factor file (CIF format) (374.0 kbytes) [ doi:10.1107/S0108768108019903/bm5056VIIIsup9.fcf ] Contains datablock VIII

	Structure factor file (CIF format) (263.5 kbytes) [ doi:10.1107/S0108768108019903/bm5056IXsup10.fcf ] Contains datablock IX

Notes:

To open or display or play some files, you may need to set your browser up to use the appropriate software. See the full list of file types for an explanation of the different file types and their related mime types and, where available links to sites from where the appropriate software may be obtained.

The download button will force most browsers to prompt for a file name to store the data on your hard disk.

Where possible, images are represented by thumbnails.

Search: From to Advanced search