An efficient synthesis of pyrazolo[3,4-b]pyridine-4-spiroindolinones by a three-component reaction of 5-aminopyrazoles, isatin, and cyclic β-diketones

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.

Manganese ferrite nanoparticle catalyzed tandem and green synthesis of spirooxindoles

PEG-400 as a nontoxic, green and reusable solvent was used for the synthesis of novel spiro-furo-pyridine-indoline-carbonitriles in the presence of a magnetically recoverable nanocatalyst.

Magnetic, acidic, ionic liquid-catalyzed one-pot synthesis of spirooxindoles

Magnetic, supported, acidic ionic liquid was synthesized and identified as an efficient catalyst for the one-pot synthesis of novel spirooxindole derivatives at mild conditions and in good yields. Three component reaction of wide variety of substituted isatins, 1,3-dimethyl-2-amino uracil, and barbituric acid, thiobarbituric acid, and dimedon as 1,3-dicarbonyl compounds gives the target compounds. Operational simplicity, low cost, high yields, environmental friendliness, wide applicability and reusability and easy recovery of the catalyst using an external magnet are the key features of this methodology.

Two methyl 3-(1H-pyrazol-4-yl)octahydropyrrolo[3,4-c]pyrrole-1-carboxylates form different hydrogen-bonded sheets

In the molecules of both methyl (1RS,3SR,3aRS,6aSR)-1-methyl-3-(3-methyl-1-phenyl-1H-pyrazol-4-yl)-4,6-dioxo-5-phenyloctahydropyrrolo[3,4-c]pyrrole-1-carboxylate, C₂₅H₂₄N₄O₄, (I), and methyl (1RS,3SR,3aRS,6aSR)-5-(4-chlorophenyl)-1-methyl-3-(3-methyl-1-phenyl-1H-pyrazol-4-yl)-4,6-dioxooctahydropyrrolo[3,4-c]pyrrole-1-carboxylate, C₂₅H₂₃ClN₄O₄, (II), the two rings of the pyrrolopyrrole fragment are both nonplanar, with conformations close to half-chair forms. The overall conformations of the molecules of (I) and (II) are very similar, apart from the orientation of the ester function. The molecules of (I) are linked into sheets by a combination of an N-H∙∙∙π(pyrrole) hydrogen bond and three independent C-H∙∙∙O hydrogen bonds. The molecules of (II) are also linked into sheets, which are generated by a combination of an N-H∙∙∙N hydrogen bond and two independent C-H∙∙∙O hydrogen bonds, weakly augmented by a C-H∙∙∙π(arene) hydrogen bond.

Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

A fast and convenient protocol for the synthesis of novel spiro[dihydropyridine-oxindole] derivatives in satisfactory yields was developed by the three-component reactions of arylamine, isatin and cyclopentane-1,3-dione in acetic acid at room temperature. On the other hand the condensation of isatin with two equivalents of cyclopentane-1,3-dione gave 3,3-bis(2-hydroxy-5-oxo-cyclopent-1-enyl)oxindole in high yields. The reaction mechanism and substrate scope of this novel reaction is briefly discussed.