3,6-Dimethyl-1-phenyl-4-(2-thien-yl)-8-(2-thienylmethyl-ene)-5,6,7,8-tetra-hydro-1H-pyrazolo[3,4-b][1,6]naphthyridine

Two isostructural 3-(5-ar-yloxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)-1-(thio-phen-2-yl)prop-2-en-1-ones: disorder and supra-molecular assembly

Two new chalcones containing both pyrazole and thio-phene substituents have been prepared and structurally characterized. 3-(3-Methyl-5-phen-oxy-1-phenyl-1H-pyrazol-4-yl)-1-(thio-phen-2-yl)prop-2-en-1-one, C23H18N2O2S (I), and 3-[3-methyl-5-(2-methyl-phen-oxy)-1-phenyl-1H-pyrazol-4-yl]-1-(thio-phen-2-yl)prop-2-en-1-one, C24H20N2O2S (II), are isomorphous as well as isostructural, and in each the thio-phene substituent is disordered over two sets of atomic sites having occupancies 0.844 (3) and 0.156 (3) in (I), and 0.883 (2) and 0.117 (2) in (II). In each structure, the mol-ecules are linked into sheets by a combination of C-H⋯N and C-H⋯O hydrogen bonds. Comparisons are made with some related compounds.

7-(4-Meth-oxy-phen-yl)-4,9-dimethyl-N-(4-methyl-phen-yl)-5,12-diaza-tetra-phen-6-amine

In the title compound, C(32)H(27)N(3)O, the fused tetra-cycilc ring system is essentially planar [r.m.s. deviation = 0.07 (7) Å]. An intra-molecular N-H⋯π(arene) inter-action and a weak intra-molecular C-H⋯N hydrogen bond may influence the mol-ecular conformation. In the crystal, weak inter-molecular C-H⋯N hydrogen bonds link the mol-ecules into centrosymmetric dimers, forming R(2) (2)(14) motifs. In addition, weak π-π stacking inter-actions with centroid-centroid distances in the range 3.578 (1)-3.739 (1) Å provide further stabilization.

2,9-Dimethyl-7-phenyl-N-(4-methylphenyl)dibenzo[b,h][1,6]naphthyridin-6-amine

The title compound, C₃₁H₂₅N₃, was synthesized from 6,4′,4′′-trimethyl-2,4-bis­(N-phenyl­amino)­quinoline and is the first structural example containing a phenyl and phenyl­amino fragment attached to a fused dibenzo[1,6]naphthyridine moiety. The fused tetra­cyclic ring system is essentially planar [r.m.s. deviation = 0.08 (3) Å]. The phenyl ring and the phenyl­amino group are inclined by 82.68 (6) and 35.31 (5)°, respectively, to the mean plane of the fused tetra­cyclic ring system. A weak intra­molecular N—H⋯π(arene) inter­action may in part influence the conformation of the mol­ecule. In the crystal, mol­ecules are linked by weak inter­molecular C—H⋯N hydrogen bonds into centrosymmetric dimers. Additional stabilization is provided by weak C—H⋯π and π–π stacking inter­actions [centroid–centroid distances = 3.834 (2) and 3.898 (1) Å].