Efficient synthesis of Some Novel Symmetrical and Unsymmetrical Pyridine bis-1,2,4-triazoles and bis-1,3,4-thiadiazoles

Abstract

A series of novel bis-1,2,4-triazoles and bis-1,3,4-thiadiazoles bearing pyridine rings was synthesised, by multistep reaction sequences, in good to high yields. Reaction of pyridine-2,5-bis-and pyridine-2,6-bis-carbohydrazides with alkyl-or arylisothiocyanates gave the corresponding bis(thiosemicarbazide) derivatives, which could be cyclised under strongly basic conditions to give novel pyridine bis(1,2,4-triazole-3-thiols). However, under strongly acidic conditions the corresponding bis(2-amino-1,3,4thiadiazoles) were obtained. The synthetic routes and spectroscopic characterisation of the new compounds are reported.

New Antibacterial 1,3,4‐Thiadiazole Derivatives With Pyridine Moiety

“…Although compounds 2f and 2g were synthesized by a different method in the literature, it was seen that the 1 H-NMR spectra results were very close. [34,48] The resulting 13 C-NMR spectrum of compound 2d is given in Figure 1, and the resulting 1 H-NMR spectrum is shown in Figure 2.…”

“…All 1 H‐NMR spectra of the synthesized compounds are provided in the supplementary file. Although compounds 2f and 2g were synthesized by a different method in the literature, it was seen that the 1 H‐NMR spectra results were very close [34,48] …”

“…[22,23] These compounds exhibit broad spectrum of biological activities, including antimicrobial, [24,25] antituberculosis, [26] antioxidant, [27] anti-inflammatory, [28] anticonvulsants, [29] antidepressant and anxiolytic, [30] antihypertensive, [31] anticancer [27,32] and antifungal. There are compounds of this class in the active ingredients of some diseases; glaucoma, [33] high altitude sickness, [34] epileptic seizures, [35] idiopathic intracranial hypertension, [36] hemiplegic migraine, [37] cystinuria, [38] obstructive sleep apnea, [39] congenital myasthenic syndromes. [40] Among the wide range of active heterocycles in the pharmacological field, pyridines and some pyridine ring systems have attracted significant attention as potential chemotherapeutic agents.…”

Synthesis of some novel pyridine compounds containing bis‐1,2,4‐triazole/thiosemicarbazide moiety and investigation of their antioxidant properties, carbonic anhydrase, and acetylcholinesterase enzymes inhibition profiles

“…X‐ray single crystallography of 1,2,4‐triazole has shown that N–H…S hydrogen bonds are dimering and linked into chains . Furthermore, bis‐1,2,4‐triazoles and bis‐1,3,4‐thiadiazoles bearing pyridine rings have been reported by Foroughifar et al …”