No abstract

In the present work, the 2‐benzoxazinonyl benzoic acid (BBA) could be isomerized to the stereogenic spiro products (SBI) via ultrasonic and basic reaction conditions. The spiro compounds (SBI) have both electrophilic and nucleophilic centers. A series of nitrogen nucleophiles such as hydrazine hydrate, glycine, 2‐aminopyridine, 2‐picolinylamine, 4‐anisidine, 4‐aminoacetophenone and carbon electrophiles such as oxiranylmethylchloride, ethylchloroacetate, chloroacetylchloride, Mannich reagents, for example, formaldehyde with piperidine or morpholine can be treated with 2‐benzoxazine‐2‐yl benzoic acid (BBA) via multicomponent reaction. The basicity of previous nucleophiles can be controlled on the course of reaction of 2‐benzoxazinonyl benzoic acid. The chemical structure of the synthesized compounds can be confirmed by microanalytical, spectral data and optimized by quantum chemical parameters.

Phthalazines have received considerable attention for their wide antimicrobial activity. Regiospecific nucleophilic attack of 4‐benzylphthalazin‐1‐ol by the 1‐oxo rather than the aza group on different alkyl halides gave novel phthalazine heterocyclic derivatives. Moreover, a variety of nucleosides bonded to electron‐withdrawing groups were synthesized using 4‐benzylphthalazine‐1‐ol. The density functional theory has been used to investigate the electronic structure of the synthesized compounds. All of the synthesized derivatives showed remarkable activity when tested against Gram‐positive and Gram‐negative bacteria, Aspergillus niger, and Candida albicans. The reactivity of these nucleosides was expected to arise from their bonding with the lone pair of N‐atom of the macromolecules of bacteria. These bonding were expected to inhibit the enzyme by forming highly stable complex with lower highest occupied molecular orbital energy. The structures of these synthesized derivatives were established by Fourier transform infrared, 1H‐NMR, and 13C‐NMR spectroscopic evidence.

A simple facile “one‐pot” synthesis of 5‐(4‐chlorophenyl)‐7‐(3,4‐dimethyl phenyl)‐2‐oxo‐2H‐pyrano[2,3‐b]pyridine derivatives via three‐component reaction of chalcone, ethyl‐2‐substituted acetate, and ammonium acetate under ultrasonic irradiation and grinding tools. The newly synthesized compounds were evaluated for their antibacterial activity against ATCC 25923, ATCC 10987, ATCC 274, and SM514. All the synthesized compounds have been characterized on the basis of their elemental analyses and spectral data.

Hydrazide‐hydrazone namely, 2‐cyano‐N′‐((1‐phenyl‐3‐[thiophen‐2‐yl]‐1H‐pyrazol‐4‐yl)methylene)acetohydrazide (3) underwent a series of reactions with some chemical reagents to construct new biologically active N‐heterocycles, for example, chromenone, benzochromenone, thiazoline, and quinolone derivatives. Treating the nitrile derivative 3 with 2,4‐dichlorobenzaldehyde and pyrazole aldehyde 1 afforded the corresponding condensed products. Some of the synthesized compounds were screened for their in vitro antitumor activities against two different human tumor cell lines including hepatocellular liver carcinoma (HepG2) and breast adenocarcinoma (MCF7) activities. Compound 3 was the most potent against the two tumors.