Adivireddy Padmaja

Synthesis, antimicrobial and antioxidant activities of substituted pyrazoles, isoxazoles, pyrimidine and thioxopyrimidine derivatives

A new class of heterocycles, substituted pyrazoles, isoxazoles, pyrimidines, thioxopyrimidines were prepared from Michael adducts, 2-(1,2-diaroylethyl)malononitrile and 2-(1,2-diarylsulfonylethyl)malononitrile by cyclocondensation with appropriate nucleophiles. The lead compounds were screened for the antimicrobial and antioxidant activities.

Synthesis and bioassay of aminosulfonyl-1,3,4-oxadiazoles and their interconversion to 1,3,4-thiadiazoles

A new class of oxadiazoles is prepared by treating aminosulfonylacetic acids with different carboxylic acid hydrazides. Interconversion of oxadiazoles to thiadiazoles is carried out with thiourea. The compounds are screened for antimicrobial and antioxidant activities.

Synthesis and antioxidant activity of a new class of mono- and bis-heterocycles.

A new class of mono‐ and bis‐heterocycles, 2‐arylsulfonylaminosulfonylmethyl‐5‐styrylsulfonylmethyloxadiazoles, pyrazolyl oxadiazoles, and isoxazolyl oxadiazoles, were synthesized and tested for their antioxidant activity. The styrylsulfonylmethyloxadiazole 5b showed good antioxidant activity when compared with the standard ascorbic acid.

Synthesis and antioxidant activity of amido-linked benzoxazolyl/benzothiazolyl/benzimidazolyl-pyrroles and pyrazoles

The amido-linked benzoxazolyl/benzothiazolyl/benzimidazolyl-pyrroles and benzoxazolyl/benzothiazolyl/benzimidazolyl-pyrazoles were prepared from the synthetic intermediates (E)-N-(benzoxazol-2-yl)cinnamamide/(E)-N-(benzothiazol-2-yl)cinnamamide/(E)-N-(1H-benzimidazol-2-yl)cinnamamides adopting simple and versatile synthetic methodologies. All the new compounds were tested for antioxidant activity. The compounds 5b, 8b and 14b displayed greater antioxidant activity when compared with the standard drug ascorbic acid. It was also observed that benzoxazolyl amido-linked derivatives displayed greater radical scavenging activity than the benzothiazolyl and benzimidazolyl amido-linked derivatives.Graphical AbstractThe amido-linked benzoxazolyl/benzothiazolyl/benzimidazolyl-pyrroles and benzoxazolyl/benzothiazolyl/benzimidazolyl-pyrazoles were prepared from the synthetic intermediates (E)-N-(benzoxazol-2-yl)cinnamamide/(E)-N-(benzothiazol-2-yl)cinnamamide/(E)-N-(1H-benzimidazol-2-yl)cinnamamides adopting simple and versatile synthetic methodologies. All the new compounds were tested for antioxidant activity. The compounds 5b, 8b and 14b displayed greater antioxidant activity when compared with the standard drug Ascorbic acid. It was also observed that benzoxazolyl amido-linked derivatives displayed greater radical scavenging activity than the benzothiazolyl and benzimidazolyl amido-linked derivatives.

One-pot Synthesis of 5-{[Bis(azolylmethylthio)]methylene}pyrimidine-2,4,6-(1H,3H,5H)-triones

A new class of hitherto unknown trisheterocycles, bisoxadiazolyl/bisthiadiazolyl pyrimidinetriones/thioxopyrimidinediones was prepared in a one‐pot reaction and their antimicrobial activity was studied.

Synthesis and antimicrobial activity of 3-aroyl-4-heteroaryl pyrroles and pyrazoles

Abstract A variety of bis heterocycles-heteroaryl pyrazoles (5) and pyrroles (6) were prepared from heteroaryl chalcones adopting 1,3-dipolar cycloaddition reaction and studied their antimicrobial activity. The compounds 5d and 5f having bromo and nitro substituents on the aromatic ring are the potent antimicrobial agents against Bacillus subtilis and Aspergillus niger.

Synthesis and antioxidant activity of a new class of sulfone/sulfonamide-linked bis(oxadiazoles), bis(thiadiazoles), and bis(triazoles)

A new class of sulfone/sulfonamide-linked bis(oxadiazoles), bis(thiadiazoles), and bis(triazoles) were prepared from the synthetic intermediates sulfonyldiacetic acid, arylsulfonylacetic acid hydrazide, and arylaminosulfonylacetic acid hydrazide adopting simple and versatile synthetic methodologies. All the new compounds were tested for their antioxidant activity. Amongst all the tested compounds, methyl-substituted bis(oxadiazoles) (8b and 11b) were found to be potential antioxidant agents. It was also observed that sulfonamide-linked bis(oxadiazoles), bis(thiadiazoles), and bis(triazoles) showed comparatively higher antioxidant activity than sulfone-linked bis(oxadiazoles), bis(thiadiazoles), and bis(triazoles).

Synthesis and antioxidant activity of pyrazolyl-oxazolines/thiazolines and isoxazolyl-oxazolines/thiazolines

A new class of pyrazolyl/isoxazolyl-oxazolines and thiazolines were synthesized from E-arylsulfonylethenesulfonylacetic acid methyl ester and tested for antioxidant activity. Among the tested compounds, 14b exhibited excellent antioxidant activity when compared with the standard ascorbic acid.

Synthesis and Antioxidant Activities of Acetamidomethylsulfonyl Bis Heterocycles-Oxazolyl/Thiazolyl/Imidazolyl-1,3,4-Oxadiazoles

A new class of acetamidomethylsulfonyl bis heterocycles‐oxazolyl‐1,3,4‐oxadiazoles, ‐thiazolyl‐1,3,4‐oxadiazoles, and ‐imidazolyl‐1,3,4‐oxadiazoles were synthesized from the synthetic intermediates, methyl 2‐((4‐aryloxazol‐2‐ylcarbamoyl)methylsulfonyl)acetate, methyl 2‐((4‐arylthiazol‐2‐ylcarbamoyl)methylsulfonyl)acetate, and methyl 2‐((4‐aryl‐1H‐imidazol‐2‐ylcarbamoyl)methylsulfonyl)acetate. All the title compounds were tested for their antioxidant activity. The oxadiazolylmethylsulfonyloxazolylacetamide displayed excellent radical‐scavenging activity when compared with the standard ascorbic acid.

Synthesis and antimicrobial activity of pyrazolyl benzoxazoles, benzothiazoles and benzimidazoles

Abstract A new class of amido-linked pyrazolyl benzoxazoles, benzothiazoles and benzimidazoles was prepared and studied for their antimicrobial activity. The chloro-substituted pyrazolyl benzothiazole is the potent antibacterial agent against Bacillus subtilis and chloro-substituted pyrazolyl benzimidazole is the potent antifungal agent against Aspergillus niger.