Anti-histaminic, anti-inflammatory and bronchorelaxant activities of 2, 7-dimethyl-3-nitro-4H pyrido [1,2-a] pyrimidine-4-one

Computational and Experimental Investigations of 7-(4-nitrophenyl)benzo[6,7]chromeno[3,2-e]pyrido[1,2-a]pyrimidin-6(7h)-one

Acstract:

In-silico studies are used for the prediction of the properties of several novel materials using computer simulation technique. The present study describes the complete description of the molecular vibrations and electronic feature of the title compound by this technique. 7-(4-nitrophenyl)benzo[6,7]chromeno[3,2-e]pyrido[1,2-a]pyrimidin-6(7H)-one was prepared by the multicomponent reaction of 2H-pyrido[1,2-a]pyrimidine-2,4(3H)-dione, 2-naphthol and p-nitrobenzaldehyde. The structure of the compound was confirmed by UV, IR, NMR (1H, 13C) and mass spectroscopic studies. The compound was further subjected to quantum chemical calculations at the level of Hartee-Fock (HF) method using Lan2DZ basis set to compute polarizability, hyperpolarizabilities, AIM approach, Natural bond orbital analysis, complete vibrational assignments, Mulliken charges, spectral analysis and HOMO-LUMO energies

Synthesis of arylidene hydrazinylpyrido[2,3-d]pyrimidin-4-ones as potent anti-microbial agents

Combination of arylidene hydrazinyl moiety with pyrido[2,3-d]pyrimidin-4-one skeleton in compounds 7‒26 results in the output of unprecedented anti-microbial agents. Arylidene hydrazinyl based on Pyrido[2,3-d]pyrimidin-4-one analoges 7‒26 prepared by the treatment of [2,3-d]pyrimidin-4-ones 6a,b with various aromatic aldehydes. The antimicrobial action for recently synthesized compounds was considered towards gram positive bacterial species (Staphylococcus aurous ATCC- 47077; Bacillus cereus ATCC-12228), gram negative bacterial species (Escherichia coli ATCC-25922; Salmonella typhi ATCC-15566) and Candida albicans ATCC-10231 as fungal strains. The antimicrobial action expanded by expanding the electron donating group in position 2 and 5 for Pyrido[2,3-d]pyrimidin-4-one core. Derivatives 13, 14, 15, 16 and 12; individually appeared hopeful anti-microbial action towards all strains utilized with inhibition zone higher than that of standard reference drug with lowest MIC.

3,4-Dihydropyrimidin-2(1H)-One Analogues: Microwave irradiated Synthesis with Antimicrobial and Antituberculosis Study

Background:

For rapid and sustainable synthesis, microwave irradiation method is serviceable. This present study deals with the preparation of oxadiazole and pyridine bearing 1,2,3,4- tetrahydro pyrimidine derivatives by microwave irradiation.

Objective:

The present study aims to carry out rapid synthesis of chloro-acetamides of oxadiazoles of Biginelli product and amino cyano derivative of pyridine by microwave-assisted heating. Our efforts are focused on the introduction of chemical diversity in the molecular framework in order to synthesize pharmacologically interesting compounds.

Methods::

Microwave irradiation was used for the synthesis of 2-((3-cyano-4-(3,4-dichloro phenyl)- 6-(4-hydroxy-3-methoxyphenyl) pyridin-2-yl) amino)-N-(5-(substituted) -(6-methyl-2-oxo -1,2,3,4- tetrahydro pyrimidin-5-yl)-1,3,4-oxadiazol-2-yl)acetamide by using Biginelli reaction. New structural analogues were confirmed by spectral studies followed by their screening for in vitro antibacterial activity against Staphylococcus aureus, Staphylococcus Pyogenus, Escherichia coli and Pseudomonas aeruginosa bacterial strains and for antifungal activity against Candida albicans, Aspergillus niger and Aspergillus clavatus by micro-broth dilution method. In vitro antimycobacterial activity determined out against (Mycobacterium tuberculosis) H37Rv strain using Lowenstein-Jensen medium.

Results:

As compared to the conventional method, microwave irradiation method is advantageous for the synthesis of 1,2,3,4-tetrahydropyrimidin derivatives. Potent antimicrobial activities and antitubercular activity were found for some of the compounds.

Conclusion:

Microwave irradiation method provided an effective way to discover a novel class of antimicrobial and antituberculosis agents. 1,2,3,4-tetrahydropyrimidin derivatives showed improved antimicrobial and good antituberculosis activity.

Regioselective synthesis of pyrimidine-fused tetrahydropyridines and pyridines by microwave-assisted one-pot reaction

A regioselective three-component reaction of α,β-unsaturated aldehydes, cyclic 1,3-dicarbonyls and 6-aminouracils in the presence of FeCl₃·6H₂O as catalyst under microwave irradiation has been demonstrated. Three-component reaction of α,β-unsaturated aldehydes like cinnamaldehyde/crotonaldehyde, cyclic 1,3-diketones such as 2-hydroxy-1,4-naphthaquinone/dimedone and 6-aminouracils provides regioselective pyrimidine-fused tetrahydropyridines tethered with cyclic 1,3-diketones. On the other hand, replacing cyclic 1,3-diketones by 4-hydroxycoumarin and keeping all other conditions the same provided a two-component pyrimidine-fused pyridines. The salient features of this methodology are operational simplicity, short reaction time, good-to-moderate yields of the products, easy purification method and regioselective products having medicinally important heterocyclic rings such as pyrimidine, tetrahydropyridine or pyridine.

Synthesis and vasodilator activity of 3,4-dihydropyrimidin-2(1H)-ones bearing urea, thiourea, and sulfonylurea moieties

A series of novel 3,4-dihydropyrimidin-2(1H)-ones bearing urea, thiourea, and sulfonylurea moieties were synthesized and pharmacologically evaluated as vasodilator agents. The most interesting vasodilators were the thiourea derivatives 6a and 6b and the urea derivatives 6f–6i and 7f–7h, although the ureas were relatively more active than thioureas. Twenty-fold more active than diazoxide, the urea 6g was the most potent vasodilator (EC50 = 0.983 ± 0.061 μmol/L) and proved to act as a voltage-gated calcium channel blocker. The lack of activity of sulfonylureas, 6k and 7j, could be attributed to their partial ionization at the physiological pH because of their acidic character. It should be interesting to investigate a larger number of compounds, including N-methylated sulfonylureas, to increase the vasodilator activity and to explore other biological models.