Microwave induced three-component synthesis and antimycobacterial activity of benzopyrazolo[3,4-b]quinolindiones.

Three series of novel 4-arylbenzo[h]pyrazolo[3,4-b]quinolin-5,6-diones 4, 7 and 9 have been efficiently obtained in good yields by three-component microwave assisted reaction between aminopyrazoles 1 or 6 (both 1-phenyl and 1-H substituted), 2-hydroxynaphthoquinone 2 and benzaldehydes 3. Compounds 4, 7 and 9 have been evaluated against fifteen Mycobacterium spp strains, and six of them have shown antimycobacterial activity. The highest inhibitory activity with MIC ≤2 μg/mL for three of these compounds (4a, 4b and 4g) was related with their highest lipophilicity and lesser polarity within these series.

Hydrogen-bonded assembly in six closely related pyrazolo[3,4-b]pyridine derivatives; a simple chain, three types of chains of rings and a complex sheet structure.

Six closely related pyrazolo[3,4-b]pyridine derivatives, namely 6-chloro-3-methyl-1,4-diphenylpyrazolo[3,4-b]pyridine-5-carbaldehyde, C(20)H(14)ClN(3)O, (I), 6-chloro-3-methyl-4-(4-methylphenyl)-1-phenylpyrazolo[3,4-b]pyridine-5-carbaldehyde, C(21)H(16)ClN(3)O, (II), 6-chloro-4-(4-chlorophenyl)-3-methyl-1-phenylpyrazolo[3,4-b]pyridine-5-carbaldehyde, C(20)H(13)Cl(2)N(3)O, (III), 4-(4-bromophenyl)-6-chloro-3-methyl-1-phenylpyrazolo[3,4-b]pyridine-5-carbaldehyde, C(20)H(13)BrClN(3)O, (IV), 6-chloro-4-(4-methoxyphenyl)-3-methyl-1-phenylpyrazolo[3,4-b]pyridine-5-carbaldehyde, C(21)H(16)ClN(3)O(2), (V), and 6-chloro-3-methyl-4-(4-nitrophenyl)-1-phenylpyrazolo[3,4-b]pyridine-5-carbaldehyde, C(20)H(13)ClN(4)O(3), (VI), which differ only in the identity of a single small substituent on one of the aryl rings, crystallize in four different space groups spanning three crystal systems. The molecules of (I) are linked into a chain of rings by a combination of C-H···N and C-H···π(arene) hydrogen bonds; those of (II), (IV) and (V), which all crystallize in the space group P ̅1, are each linked by two independent C-H···O hydrogen bonds to form chains of edge-fused rings running in different directions through the three unit cells; the molecules of (III) are linked into complex sheets by a combination of two C-H···O hydrogen bonds and one C-H···π(arene) hydrogen bond; finally, the molecules of (VI) are linked by a single C-H···O hydrogen bond to form a simple chain.

Two similarly substituted benzo[h]pyrazolo[3,4-b]quinoline-5,6(10H)-diones: supramolecular structures in two and three dimensions.

The molecules of 8-methyl-7,10-diphenyl-5H-benzo[h]pyrazolo[3,4-b]quinoline-5,6(10H)-dione, C(27)H(17)N(3)O(2), (I), are weakly linked into chains by a single C-H...

(E)-N-{[6-chloro-4-(4-chlorophenyl)-3-methyl-1-phenyl-1H-pyrazolo[3,4-b]pyridin-5-yl]methylene}benzene-1,2-diamine: a three-dimensional framework structure built from only two hydrogen bonds.

The molecules of the title compound, C(26)H(19)Cl(2)N(5), are conformationally chiral, with none of the aryl groups coplanar with the pyrazolo[3,4-b]pyridine core of the molecule. A single unique N-H..