Synthesis and Biological evaluation of some newer Pyrazole Derivatives

Pyrazoline is a 5-membered heterocyclic moiety has two adjoining nitrogen iotas and three carbon particles inside the ring. Pyrazoline subordinate are related wide scope of pharmacological and restorative exercises, for example, antibacterial, antifungal, pain relieving, calming, hostile to parasitic, against malarial, against oxidant. The ongoing work of exploration is fundamentally engaged at the revelation and improvement of a progression of 1,3,5-trisubstituted pyrazoline. A progression of new 1-phenyl-3-(4-nitrophenyl)- 5-(subbed phenyl) pyrazoline subordinates (2a-2j) were blended by the response of subbed acetophenone and subbed benzaldehyde within the sight of fluid sodium hydroxide arrangement by Claisen Schmidt buildup system. The subbed chalcone were integrated which is additionally dense with phenyl hydrazine in ethanol and results in the definition of conclusive subordinates of pyrazoline (2a-2j). The response blend was observed by TLC and the last mixes were refined by recrystallization from wanted dissolvable. All the structures of blended mixes were affirmed by FTIR, 1H NMR, mass unearthly information and essential investigation. All the recently combined mixes (2a-2j) were assessed for antibacterial and antifungal movement. Mixes 2f, 2i and 2h showed powerful inhibitory impact against on strains of both bacterial and parasitic species.

Synthetic Approaches and Biological Significance of Oxazolone Moieties: A Review

Oxazolone is a five-membered heterocyclic compound which is also known as azlactone. It contains one oxygen and one nitrogen as heteroatoms, which exist in five isomeric forms, according to the carbonyl group's location and the double bonds such as: 5 (4)-oxazolones, 5 (2) – oxazolones, 2 (3)-oxazolones, 4 (5)-oxazolones, and 2 (5)-oxazolones. 5 (4)-oxazolones is the most important heterocyclic moiety among all isomeric form of oxazolones. It is classified into two classes: saturated and unsaturated oxazolones. It is synthesized by various synthetic routes. Oxazolones are reported to exhibit various pharmacological activities such as antimicrobial, anti-inflammatory, anticancer, anti-HIV, antiangiogenic, anticonvulsant, sedative, cardiotonic, antidiabetic activity, etc.

Electron-Deficient Acetylenes as Three-Modal Adjuvants in SNH Reaction of Pyridinoids with Phosphorus Nucleophiles

Publications covering a new easy metal-free functionalization of pyridinoids (pyridines, quinolines, isoquinolines, acridine) under the action of the system of electron-deficient acetylenes (acetylenecarboxylic acid esters, acylacetylenes)/P-nucleophiles (phosphine chalcogenides, H-phosphonates) are reviewed. Special attention is focused on a SNH reaction of the regioselective cross-coupling of pyridines with secondary phosphine chalcogenides triggered by acylacetylenes to give 4-chalcogenophosphorylpyridines. In these processes, acetylenes act as three-modal adjuvants (i) activating the pyridine ring towards P-nucleophiles, (ii) deprotonating the P-H bond and (iii) facilitating the nucleophilic addition of the P-centered anion to a heterocyclic moiety followed by the release of the selectively reduced acetylenes (E-alkenes).

On the synthesis of a novel chiral phosphorodiamidic acid containing the α-phenylethyl moiety: Insights in its conformation and reactivity

A few years ago, the synthesis of chiral phosphoric acids supported on chiral BINOL frameworks was accomplished by T. Akiyama and M. Terada. Subsequent relevant applications demonstrated the importance of chiral phosphoric acids as privileged chiral inducers in asymmetric organocatalysis. In the present report we discuss the development of novel chiral phosphorodiamidic acids derived from C2-symmetric trans-1,2-diaminocyclohexane aliphatic frameworks. The preparation of the new chiral Brønsted acids, based on the intermediacy of a 1,3,2-diheterophospholan-2-oxide moiety, turned out to be challenging since several plausible synthetic methodologies proved to be ineffective. Furthermore, the five membered heterocyclic moiety turned out to be easily hydrolyzed when exposed to nucleophilic alcohols or water. Complementary to the successful multistep synthesis reported here, it was possible to obtain crystals of the key precursor of the desired phosphorodiamidic acid, which proved suitable for X-ray diffraction analysis and hence to establish important conformational characteristics of the novel heterocycle.

Microwave Assisted Synthesis and Antibacterial Evaluation of 1, 3, 4-Thiadiazole Derivatives

1,3,4-Thiadiazole is an important heterocyclic moiety, forms an integral core structural component of different categories of drugs such as antimicrobial, antitubercular, anti-inflammatory, antiepileptic, antiviral, antineoplastics, and analgesic agents. It is a key moiety in current discovery and designing of new drugs. The compounds were synthesised by both conventional method and microwave method. The targeted derivatives can be synthesised in a shorter time under microwave condition than under conventional reaction condition. Their structures were confirmed by FT-IR and NMR Spectroscopy. Antibacterial property of two synthesised analogs were evaluated by Agar well diffusion method against Escherichia coli and Staphylococcus aureus. The results of antibacterial activity showed that both the compounds were active against Staphylococcus aureus and inactive against Escherichia coli. Results of invitro studies showed that modifications in SB-2-PHB and SB-8-PHB will make it as a promising lead molecule for further research.

Quinoxaline: A chemical moiety with spectrum of interesting biological activities

: Quinoxaline (C8H6N2), commonly called 1,4-diazanaphthalene, 1,4-benzodiazine, or benzopyrazine, is a very potent nitrogenous heterocyclic moiety consisting of a benzene ring fused with the pyrazine ring. A number of different methods for the synthesis of quinoxaline derivatives have been reported in the literature, but the most effective method, commonly used for the synthesis of quinoxaline analogues involves the condensation of substituted o-phenylenediamines with 1, 2- dicarbonyl compounds in the presence of different catalyst(s). The presence of different types of catalysts and their concentration affects the overall yield of the product. Quinoxaline not only plays an important role as an organic reaction intermediate but also has a wide spectrum of interesting biological activities viz. antibacterial, antifungal, anticancer, anti-inflammatory, antiviral, and antiprotozoal activity, etc. Some commercially available drug molecules containing quinoxaline moiety are echinomycin (as antibacterial, antineoplastic, and nucleic acid inhibitor), triostins (cyclic desipeptide as an antibacterial agent), dioxidine and mequindox (as antibacterial agents), carbadox (controlling swine dysentery), desoxycarbadox (as swine growth promoter) and panadipion (as hepatoprotective agent), etc. A large number of quinoxaline analogues possessing different biological activities and their synthetic procedures have been patented worldwide.

The Pseudo-Symmetric N-benzyl Hydroxyethylamine Core in a New Series of Heteroarylcarboxyamide HIV-1 Pr Inhibitors: Synthesis, Molecular Modeling and Biological Evaluation

New series of compounds containing both heterocycle moieties and pseudo-symmetric hydroxyethylamine core were obtained using a simple synthetic path that can provide a library of compounds in few steps and high yields. Furthermore, diversity-oriented synthesis was studied to change different functionalities according to needs. The in vitro inhibition activity against recombinant HIV-1 protease was evaluated. A beneficial effect of this class of compounds can be obtained either for the presence of a bis-benzyl group into the core and for the heterocyclic moiety in P1, specifically the indole ring. Docking analysis was also reported.

An Expedient Approach to Pyrazolo[3,4-b]pyridine-3-carboxamides via Palladium-Catalyzed Aminocarbonylation

Pyrazolo[3,4-b]pyridine is a privileged scaffold found in many small drug molecules that possess a wide range of pharmacological properties. Efforts to further develop and exploit synthetic methodologies that permit the functionalization of this heterocyclic moiety warrant investigation. To this end, a series of novel 1,3-disubstituted pyrazolo[3,4-b]pyridine-3-carboxamide derivatives have been prepared by introducing the 3-carboxamide moiety using palladium-catalyzed aminocarbonylation methodology and employing CO gas generated ex situ using a two-chamber reactor (COware®). The functional group tolerance of this optimized aminocarbonylation protocol is highlighted through the synthesis of a range of diversely substituted C-3 carbox­amide pyrazolo[3,4-b]pyridines in excellent yields of up to 99%.

SYNTHESIS OF PIPERINE - PIPERAZINE ANALOGUES AND THEIR ANTIBACTERIAL ACTIVITY

In the current study, a series of piperine – piperazine analogues (5a to 5f) were designed and synthesized. The piperine was isolated from pepper and used for the conjugation with heterocyclic moiety for better biological activity. The piperazine heterocyclic was chosen for conjugation with piperine. The newly synthesized structures were determined by IR, 1H NMR and 13C NMR spectral data. The compounds were examined for their anti‐microbial activity against gram-positive (Bacillus subtilis) and gram-negative (Vibrio cholerae) bacteria using the agar well diffusion method. The newly synthesized compounds exhibited capable activities against V. cholerae and B. subtilis and it showed minimum inhibitory concentration. Among all the synthesized compounds, 5f has the highest activity (26 mm) against gram-positive bacteria and (29mm) against gram-negative bacteria. The remaining compounds showed appreciable antibacterial activity. The enhanced activity of the synthesized compounds may be due to the presence of conjugated amide linkage with the natural product piperine and piperazine heterocyclic molecule. The substituents present on the aromatic (nitro-substituted) ring also influenced the activity of the compound.