Palladium-catalyzed regioselective direct C H arylation of pyrazolo[3,4- d ]pyrimidines

Crystal structure and Hirshfeld surface analysis of 3-(4-meth-oxy-phen-yl)-1-methyl-4-phenyl-1H-pyrazolo-[3,4-d]pyrimidine

In the title mol-ecule, C19H16N4O, the planar pyrazolo-pyrimidine moiety is inclined to the attached phenyl rings by 35.42 (4) and 54.51 (6)°. In the crystal, adjacent mol-ecules are linked into chains parallel to [110] and [10] by C-H⋯O and C-H⋯N hydrogen bonds. Additional C-H⋯π(ring) inter-actions lead to the formation of the final three-dimensional network structure. The Hirshfeld surface analysis of the title compound suggests that the most significant contributions to the crystal packing are from H⋯H (48.2%), C⋯H/H⋯C (23.9%) and N⋯H/H⋯N (17.4%) contacts.

1-Methyl-4-phenyl-3-[4-(trifluoromethyl)phenyl]-1H-pyrazolo[3,4-d]pyrimidine

In the title molecule, C19H13F3N4, the pyrazolopyrimidine unit is slightly non-planar [dihedral angle between the five- and six-membered rings = 3.03 (15)°]. In the crystal, offset head-to-tail π-stacking interactions between pyrazolopyrimidine units [centroid–centroid separation = 3.665 (2) Å] together with weak C—H...N hydrogen bonds form stepped chains propagating along the c-axis direction. The structure was refined as a two-component twin.

1-Methyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one

The title molecule, C6H6N4O, is essentially planar [dihedral angle between the rings = 0.46 (9)°]. The crystal structure consists of sheets of molecules lying parallel to (-111) formed by a combination of N—H...O, C—H...O and C—H...H hydrogen bonds. The sheets are connected through π–π stacking interactions.

N,N-Dimethyl-1H-pyrazolo[3,4-d]pyrimidin-4-amine monohydrate

The asymmetric unit of the title compound, C7H9N5·H2O, consists of two formula units differing slightly in the orientation of the dimethylamino groups. In the crystal, a combination of O—H...N and N—H...O hydrogen bonds involving the water molecules of crystallization, as well as slipped π-stacking interactions between pyrazolopyrimidine units form layers parallel to thebcplane.

Three successive and regiocontroled palladium cross-coupling reactions to easily synthesize novel series of 2,4,6-tris(het)aryl pyrido[1′,2′:1,5]pyrazolo[3,4-d]pyrimidines

The first access to tris(het)arylated pyrido[1′,2′:1,5]pyrazolo[3,4-d]pyrimidine derivatives is reported.