S. Vijaya Laxmi

Synthesis and evaluation of chromenyl barbiturates and thiobarbiturates as potential antitubercular agents.

A novel series of barbiturate and thiobarbiturate analogs of 2-benzoyl-3-methyl-5-oxo-5H-furo[3,2-g]chromene-6-carbaldehydes (3a-g and 4a-d, respectively) and 6-methyl-4,8-dioxo-4,8-dihydropyrano[3,2-g]chromenes (7a-c), were synthesized and evaluated for their antitubercular activities against Mycobacterium tuberculosis H37RV, and cytotoxicity (CC(50)) in the VERO cell MABA assay. The results indicate that the furanochromene series of compounds (3a-g and 4a-d) showed only weak to moderate antitubercular activity. However, the pyranochromene analog 7b showed good antitubercular activity (IC(90): 5.9μg/mL) and cytotoxicity (CC(50): 14.27μg/mL). The antitubercular activity of 7b was superior to the antituberculosis drug, pyrazinamide (PZA; IC(90): >20μg/mL). Analog 7b was considered to be a lead compound for subsequent structural optimization.

Synthesis and antimicrobial activity of coumarin pyrazole pyrimidine 2,4,6(1H,3H,5H)triones and thioxopyrimidine4,6(1H,5H)diones

A series of 5-((3-(2-oxo-2H-chromen-3-yl)-1-phenyl-1H-pyrazol-4-yl)methylene)pyrimidine-2,4,6(1H,3H,5H)-trione (4a–f) and dihydro-5-((3-(2-oxo-2H-chromen-3-yl)-1-phenyl-1H-pyrazol-4-yl)methylene)-2-thioxopyrimidine-4,6(1H,5H)-dione (5a–f) derivatives were synthesized by the condensation of 3-(2-oxo2H-chromen-3-yl)-1-phenyl-1H-pyrazole-4-carbaldehyde (3a–f) with barbituric acid and thiobarbituric acid in acetic acid under microwave irradiation method. The newly synthesized compounds were evaluated for their antibacterial activity against Bcillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeoginosa, and Klebsiella pneumoniae. All the compounds were found to be moderately active against used microorganisms, whereas compounds (4d) and (4e) exhibited good antifungal activity against Aspergillus niger.

Expeditious Pechmann Condensation by Using Biodegradable Cellulose Sulfuric Acid as a Solid Acid Catalyst

A facile synthesis of coumarins was performed in excellent yields via Pechmann condensation by using different type of phenols and ethylacetoacetates under solvent–free media using both conventional method and microwave irradiation in short reaction times is described. The reaction workup is very simple, and the catalyst can be easily separated from the reaction mixture and reused several times in subsequent reactions.

Cellulose Sulfuric Acid: An Efficient Biodegradable and Recyclable Solid Acid Catalyst for the Synthesis of 1-Oxo-hexahydroxanthene

Abstract A series of 1-oxo-hexahydroxanthene derivatives was synthesized at room temperature in solid state from substituted salicylaldehydes and substituted 1,3-hexanediones in the presence of a catalytic amount of cellulose sulfuric acid. The results showed that the reaction performed under solid-state conditions was benign to the environment, with higher yields and more convenient workup.

Xanthan Sulfuric Acid: A New and Efficient Biosupported Solid Acid Catalyst for the Synthesis of 3,4-Dihydropyrimidin-2(1H)-Ones

Abstract Xanthan sulfuric acid (XSA) is employed as a recyclable catalyst for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones. These syntheses were performed via a one-pot, three-component condensation of aldehydes, amines, and urea/thiourea under solvent-free conditions. GRAPHICAL ABSTRACT

Synthesis, single crystal X-ray studies and antimicrobial activities of novel Indole barbiturates

A novel series of N-substituted 2-phenyl indole derivatives incorporating barbituric acid have been synthesised and the chemical structures of the resulting molecules were characterised by means of IR, NMR and mass spectra. The antimicrobial activities of these compounds were investigated. Significant improvement in the antimicrobial activity can be achieved, in the presence of Cl and Br substituents on phenacyl moiety at para position. Single crystal X-ray analysis was also performed for the compound 6b in order to determine the crystal structure.

Photochemical synthesis and anticancer activity of barbituric acid, thiobarbituric acid, thiosemicarbazide, and isoniazid linked to 2-phenyl indole derivatives.

Abstract2-Phenyl-1H-indole-3-carbaldehyde-based barbituric acid, thiobarbituric acid, thiosemicarbazide, isoniazid, and malononitrile derivatives were synthesized under photochemical conditions. The antitumor activities of the synthesized compounds were evaluated on three different human cancer cell lines representing prostate cancer cell line DU145, Dwivedi (DWD) cancer cell lines, and breast cancer cell line MCF7. All the screened compounds possessed moderate anticancer activity, and out of all the screened compounds, 5-{1[2-(4-chloro-phenyl)2-oxo-ethyl]-2-phenyl-1H-indole-3-ylmethylene}-2-thioxo-dihydro-pyrimidine-4,6-dione (2b) and 5-{1[2-(4-methoxy-phenyl)2-oxo-ethyl]-2-phenyl-1H-indole-3-ylmethylene}-2-thioxo-dihydro-pyrimidine-4,6-dione (2d) exhibited marked antitumor activity against used cell lines. Additionally, barbituric acid derivatives were selective to inhibit cell line DWD and breast cancer cell lines.

Suzuki–Miyaura coupling of quinazolines containing an unprotected NH2 group: Synthesis and biological testing of quinazoline derivatives

ABSTRACT A robust approach to 4-amino quinazoline bi-aryl compounds was developed through Suzuki–Miyaura coupling reaction of quinazoline containing an unprotected NH2 group and arylboronic acids. Pd(dcpf)Cl2 was found to be an efficient catalyst for the reaction. All the compounds were evaluated for antimicrobial activity against gram-positive and gram-negative bacteria and fungi. One of the compounds, 3l, found to be more active against Candida albicans than the standard Miconazole. GRAPHICAL ABSTRACT