One-pot, four-component synthesis of spiroindoloquinazoline derivatives as phospholipase inhibitors

New Bis(pyrazolo[5,1-b]quinazolines) and Bis(9H-xanthenediones) Linked to Alkane Cores: One-Pot Synthesis, Antibacterial Screening, and SAR Study

Effective one-pot methods were used to synthesize some new alkane-linked bis(pyrazolo[5,1-b]quinazolines) and bis(9H-xanthenediones). The first series was produced, in 80-88 % yields, via the reaction of one equivalent of the appropriate bis(aldehydes) with two equivalents of 1H-pyrazole-3,5-diamine and dimedone in DMF at 150 °C for 5-6 h. The second series was prepared, in 82-89 % yields, via the reaction one equivalent of the appropriate bis(aldehydes) with four equivalents of dimedone in acetic acid at 120 °C for 4-5 h. The new products displayed a broad range of antibacterial activity against different bacterial strains. Generally, the antibacterial activity of the alkane-linked bis(pyrazolo[5,1-b]quinazoline) units is more than 2-fold their bis(9H-xanthenedione) analogues. The (p-tolylthio)methyl)-linked bis(pyrazolo[5,1-b]quinazolines) demonstrate the best antibacterial activity with MIC/MBC values up to 3.3/6.6 μM.

The versatility of DABCO as a reagent in organic synthesis: a review

DABCO (1,4-diazabicyclo[2.2.2]octane) has garnered a lot of interest for numerous organic transformations since it is a low-cost, environmentally friendly, reactive, manageable, non-toxic and basic organocatalyst with a high degree of selectivity. Moreover, DABCO functions as a nucleophile as well as a base in a variety of processes for the synthesis of a wide array of molecules, including carbocyclic and heterocyclic compounds. Protection and deprotection of functional groups and the formation of carbon-carbon bonds are also catalyzed by DABCO. The reagent also finds applications in the synthesis of functional groups like isothiocyanate, amide and ester. Application of DABCO in cycloaddition, coupling, aromatic nucleophilic substitution, ring-opening, oxidation and rearrangement reactions is also noteworthy. This is a state of the art review that has encompassed a variety of processes for the synthesis of organic frameworks using DABCO.

Catalyst-free synthesis of acenaphthoindolopyrimidine derivatives

A one pot three component reaction of acenaphthoquinone, barbituric acid/thiobarbituric acid/N,N-dimethyl barbituric acid and arylamines in ethanol for the synthesis of acenaphthoindolopyrimidine derivatives is reported. The reactions take place without a catalyst and gentle conditions. This method is facile and has some benefits such as, readily available starting materials, green solvent, catalyst-free, no column chromatographic purification and good to high yields.

Facile Multicomponent Synthesis, Computational, and Docking Studies of Spiroindoloquinazoline Compounds

Synthesis of spiroindoloquinazolines via one-pot three-component condensation reactions of tryptanthrin, malononitrile or ethylcyanoacetate, and nucleophiles was carried out in MeOH using triethylamine as the base catalyst under reflux conditions. This method has the advantages of short reaction time, excellent yields, and an easy work-up procedure. The structural properties of the compound 4c {2-amino-6-methyl-spiro-[12H]Indolo(2,1-b)quinazoline-12-one]12',4-pyrano(2,3-c)pyrazole]-3-carbonitrile} and the obtained crystal were analyzed by the DFT theoretical calculation method, using the B3LYP 6-311G(d,p) basis set and were found to be in agreement with the experimental results. The importance of biological application and drug design of the same compound was verified by molecular docking studies.

Tryptanthrin and Its Derivatives in Drug Discovery: Synthetic Insights

Tryptanthrin is a golden-yellow, naturally occurring alkaloid that can be obtained from multiple sources and through different synthetic methodologies. This tetracyclic compound displays several relevant biological activities. The potential of this tetracyclic alkaloid has been widely explored, and several researchers have focused their attention on expanding the variety of tryptanthrin derivatives by using a range of synthetic strategies. In this short review, we aim to address recent developments in the synthesis of the tryptanthrin core, as well as the development of new strategies employed by synthetic organic chemists to obtain novel tryptanthrin derivatives with potential biological activity, using different tools from the chemists’ toolbox, such as photocatalysis, solvent-free approaches, and multicomponent reactions.

One-pot multi-component synthesis of novel chromeno[4,3-b]pyrrol-3-yl derivatives as alpha-glucosidase inhibitors

A green and efficient one-pot multi-component protocol was developed for the synthesis of some novel dihydrochromeno[4,3-b]pyrrol-3-yl derivatives through the reaction of arylglyoxals, malono derivatives, and different 4-amino coumarins in ethanol at reflux condition. In this method, all products were obtained in good to excellent yield. Next, all synthesized derivatives were evaluated for their α-glucosidase inhibitory activity. Most of the compounds displayed potent inhibitory activities with IC₅₀ values in the range of 48.65 ± 0.01–733.83 ± 0.10 μM compared to the standard inhibitor acarbose (IC₅₀ = 750.90 ± 0.14 μM). The kinetic study of compound 5e as the most potent derivative (IC₅₀ = 48.65 ± 0.01 μM) showed a competitive mechanism with a K_i value of 42.6 µM. Moreover, docking studies revealed that dihydrochromeno[4,3-b]pyrrol-3-yl effectively interacted with important residues in the active site of α-glucosidase.

One-pot, sequential four-component synthesis of novel heterocyclic [3.3.3] propellane derivatives at room temperature

An efficient, one-pot, two-step, four-component reaction for the synthesis of propellane derivatives is described by the condensation reaction between acenaphthenequinone, malono derivatives, primary amines and β-ketoester or β-diketone derivatives in the presence of triethylamine in ethanol at room temperature. Using this procedure, all the products were obtained in good to excellent yields.

Eco-friendly polyethylene glycol (PEG-400): a green reaction medium for one-pot, four-component synthesis of novel asymmetrical bis-spirooxindole derivatives at room temperature

PEG-400 has been used as a green and biodegradable polymeric solvent for the one-pot, two-step, multi-component synthesis of novel asymmetrical bis-spirooxindole derivatives by the reaction of N-alkyl isatin, isatin derivatives, alkylmalonates and C–H activated carbonyl compounds in the presence of K₂CO₃ at room temperature. Using this procedure, all the products were obtained in good to excellent yields.

PEG-400 has been used for the synthesis of novel asymmetrical bis-spirooxindoles by the reaction of N-alkyl isatin, isatin derivatives, alkylmalonates and C–H activated carbonyl compounds in the presence of K₂CO₃ at room temperature.