Synthesis of 3‐arylsulfonylmethyl‐1,2,4‐oxadiazole‐5‐carboxylic acid derivatives

Abstract

Several new 3‐arylsulfonylmethyl‐1,2,4‐oxadiazole‐5‐carboxylic acid derivatives have been synthesized. A typical example, 3‐[(4‐chlorophenylsulfonyl)methyl]‐1,2,4‐oxadiazole‐5‐carboxylic acid ethyl ester (2c), was prepared from the reaction of 2‐(4‐chlorophenylsulfonyl)acetamide oxime (1c) with ethyl oxalyl chloride. The hydrazide derivative (3f) showed antihypertensive activity in rats. Various structural modifications to improve activity are discussed.

Contributions to the chemistry of 3‐cyanoacetylhydrazono‐2‐indolinones and X‐ray structure of Z‐3‐cyanoacetylhydrazono‐2‐indolinone monohydrate

“…Ring-opening transformation into aldehyde acylhydrazones has also been observed [26] when 1,3,4-oxadiazoline derivatives were simply dissolved in dimethyl sulfoxide. According to our earlier experiences in the chemistry of oxadiazolines, 1 H NMR spectra are less informative and comprehensive.…”

“…Recently, a number of 1,3,4-oxadiazoline derivatives also with free endocyclic NH group have been published [25][26][27][28][29][30][31] and the cyclic structure was suggested on the basis of IR and 1 H NMR spectral data. Ring-opening transformation into aldehyde acylhydrazones has also been observed [26] when 1,3,4-oxadiazoline derivatives were simply dissolved in dimethyl sulfoxide. According to our earlier experiences in the chemistry of oxadiazolines, 1 H NMR spectra are less informative and comprehensive.…”

Design, Synthesis, and Biological Evaluation of N-Carboxyphenylpyrrole Derivatives as Potent HIV Fusion Inhibitors Targeting gp41

“…The Paal-Knorr reaction was performed with or without glacial acetic acid as solvent under microwave irradiation in a sealed tube at 100–150 °C for 10 min 24. Microwave irradiation greatly reduced reaction time and byproducts, resulting in yields ranging from 50 to 88%, which was higher than the 28–56% in the traditional condition.…”

“…The 1,2,4-oxadiazole derivatives B 1 -B 11 were synthesized by the acylation of amidoxime,24 as shown in Scheme 2. Cyanobenzoic acids or ester were treated with hydroxylamine hydrochloride in the presence of 8-hydroxyquinoline25 to produce corresponding benzamidoximes 4 – 6 , respectively.…”

Synthesis, in silico Studies, and Anticonvulsant Activity of 1,3,4-Oxadiazole Derivatives

“…1,3,4-Oxadiazoles are heterocyclic compounds with an oxygen atom and 2 nitrogen atoms at the third and fourth positions, and they are found to be an important class of compounds in pharmaceutical chemistry because of their potential pharmacophore with diverse biological activities [1]. They have been reported for various activities such as anti-inflammatory [2], anticonvulsant [3], antimicrobial [4], ulcerogenic [5], anti-HIV [6], antifungal [7], anticancer [8], antihypertensive [9], antitubercular [10] and analgesic [11] etc.…”