Recent Progress in the Chemistry of Pyridazinones for Functional Group Transformations

In-silico Screening and Synthesis of Benzo[c]Pyridazines Targeting N-Methyl D-Aspartate Glutamate Receptor for the Treatment of Seizures

This study focuses on synthesizing novel benzopyridazine compounds with an evaluation of their anti-epileptic activity by in-silico screening and MES test. The compounds were synthesized under controlled conditions by the reaction of the substituted anilines with sodium nitrite, followed by the reaction with cyanoacetamide, substituted urea, ethanol, and water. The final compounds (5a-d; 6a-d) were tested for antiepileptic activity by in-silico screening targeting N-Methyl D-Aspartate glutamate receptor (PDB ID:5IPV). The screened compounds are also evaluated by in vivo test (MES) by taking phenytoin as a standard drug. The results of the whole study were satisfactory with the yield of the compounds in the range of 88 % to 96 %. The results of in- silico, screening showed that compounds 6a and 6c have far more binding energy compared with standard phenytoin (6a -7.5 Kcal/mol. ; 6c -7.6 Kcal/mol. and Phenytoin -6.5 Kcal/mol.). The TD50 values of synthesized compounds (6a-6d) are observed to be significantly higher than those of standard phenytoin. The PI values of several synthetic compounds (6a and 6c) were found to be higher (55.8 % and 58.0 %) than the current antiepileptic medicine phenytoin (55.6 %), demonstrating the synthesized compound's safety potential.

A New Method for the Synthesis of N, N-Diethyl-m-Methylbenzamide from m-Toluic Acid and Diethylamine Using 1,1'-Carbonyl-di-(1,2,4-triazole) (CDT) as Coupling Agent

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A new, simple method for the synthesis of N, N-dietyl-m-methylbenzamide (DEET) from m-toluic acid and diethylamine using 1,1'-carbonyl-di-(1,2,4-triazole) (CDT) as a coupling agent has been performed. The basic principles of activated carbonyls have been explored with the ability to prepare new amides easily. All reaction by-products are water-soluble as well as removed by filtration, the reaction could be purified easily in an aqueous solution by liquid-liquid extraction, and the product DEET was high purity. This experimental efficiency is about 94-95%, purity (HPLC): 97-98%.

Metal-Free Synthesis of Benzimidazoles via Oxidative Cyclization of d-Glucose with o-Phenylenediamines in Water

d-Glucose has been identified as an efficient C1 synthon in the synthesis of benzimidazoles from o-phenylenediamines via an oxidative cyclization strategy. Isotopic studies with ¹³C₆-d-glucose and D₂O unambiguously confirmed the source of methine. The notable features of this method include the following: broad functional group tolerance, a biorenewable methine source, excellent reaction yields, a short reaction time, water as an environmentally benign solvent, and the synthesis of vitamin B₁₂ component on the gram scale.

Copper-catalysed N-arylation of 5-aminopyrazoles: a simple route to pyrazolo[3,4-b]indoles

A copper-catalysed intramolecular N-arylation of 5-aminopyrazoles is demonstrated for the first time. Highly substituted pyrazolo[3,4-b]indoles are synthesized. In particular, the indole core is decorated with halogens and alkyl and methoxy groups. Furthermore, a selective N-arylation of unsymmetrical diaryl bromide containing pyrazoles is exemplified, resulting in valuable pyrazolo[1,5-a]benzimidazoles.