Synthesis and Antimicrobial Activity of Pyridines Bearing Thiazoline and Moieties.

Self Cite

A series of 5-phenyl-1-(3-pyridyl)-1H-1,2,4-triazole-3-carboxylic acid derivatives 4-10 were synthesized by rearrangement of 4-(3-pyridyl)-hydrazono-2-phenyl-2-oxazolin-5-one 3 in the presence of different nucleophiles to afford derivatives 4, 7, and 8, while hydroxamic acid derivative 6 was prepared from reaction of methyl ester 4 with hydroxylamine hydrochloride. Semicarbazide 9 and thiosemicarbazide 10, derivatives of the 5-phenyl-1-(3-pyridyl)-1H-1,2,4-triazole-3-carboxylic acid, were synthesized via hydrazide 8 with potassium cyanate and appropriate isothiocyanate, respectively. The structures of the synthesized compounds were confirmed by elemental analyses, IR, (1)H-NMR, and mass spectra. The results of the anti-inflammatory activity of the synthesized derivatives showed that most of the tested compounds 4-10 showed significant inhibition against carrageenan-induced rat paw edema in albino rats. Derivatives 4 and 8 showed promising results and were found to be equipotent or more potent than Indomethacin and Celecoxib as reference drugs at two dose levels, 5 and 10 mg/kg, and they have no ulcerogenic activity.

Section: Anti-inflammatory Activitysupporting

confidence: 94%

Section: Introductionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis of 5‐Phenyl‐1‐(3‐pyridyl)‐1H‐1,2,4‐triazole‐3‐carboxylic Acid Derivatives of Potential Anti‐inflammatory Activity

Rabea

El-Koussi²,

Hassan

et al. 2006

Self Cite

“…Percentage-inhibition data for non-invasive blood pressure measurement are given in Table 2. Some of the compounds, which show good antihypertensive activity, were further assessed by invasive blood pressure (IBP) measurement [22,23]. The results for invasive blood pressure measurement are given in Table 3 and Fig.…”

Section: Pharmacologymentioning

confidence: 99%

Synthesis, Antihypertensive Activity, and 3D‐QSAR Studies of Some New p‐Hydroxybenzohydrazide Derivatives

Bhole¹,

Bhusari²

2010

p-Hydroxybenzohydrazide 2 on treatment with aromatic/aliphatic aldehyde followed by cyclization with carbon disulphide afforded compounds 4a-4n. Also, compound 2 by treatment of substituted isothiocyanate followed by the treatment of chloroacetic acid yields the corresponding compounds 6a-6i. All the test compounds were assayed for antihypertensive activity by non-invasive blood pressure measurement and invasive blood pressure measurement methods. The test compounds showed significant antihypertensive activity. The intact compounds were subjected to 3D-QSAR studies. The 3D-QSAR analysis was carried out by PHASE program and a statistically reliable model with good predictive power (r(2) = 0.98, q(2) = 0.74) was achieved. The 3D-QSAR plots illustrated insights into the structure-activity relationship of these compounds which may aid in the design of potent p-hydroxybenzohydrazide derivatives as antihypertensive agents.

“…In particular, 1,2,4-triazoles and their 3-thioxo analogues, have emerged as potent antibacterial agents, [11][12][13].The imidazole nucleus has also been studied as a potential antibacterial agent [14,15]. Moreover, the thiazolidinone nucleus is present in many compounds that have antibacterial activity [16,17]. Finally, it was reported that heterocyclic compounds substituted with saturated cycloamino substituents have shown enhanced activity against Euglena, and some derivatives with piperazine ring were shown to be active against Gram-positive bacteria [18,19].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and In Vitro Antibacterial Evaluation of Novel Imidazo[2′, 1′:5, 1]‐1, 2, 4‐triazolo[4, 3‐c]‐quinazoline Derivatives of 5‐Thioxo‐1, 2, 4‐triazole, 4‐Oxothiazolidine, and their Open‐chain Counterparts

Nasr

Gineinah

El‐Bendary

2003

Two novel series of imidazo[2', 1':5, 1]-1, 2, 4-triazolo[4, 3-c]quinazolines bearing 5-thioxo-1, 2, 4-triazoles, 6a-f, and 4-oxothiazolidines, 7a-f, were synthesized from corresponding thiosemicarbazide derivatives, 5a-f. The stepwise methodology applied to the preparation of compounds 5a-f was initiated with reaction of the parent 3-amino-1, 2, 4-triazolo[4, 3-c]quinazolines, 2, with ethyl 2-chloroacetoacetate resulting in annelation of the imidazole ring to give esters, 3a-c. However, hydrazinolysis of these ester derivatives gave the corresponding acid hydrazides, 4a-c, which on reaction with the appropriate alkyl isothiocyanate yielded compounds 5a-f. In turn, compounds 5, were cyclized with potassium hydroxide or with ethyl bromoacetate to give the corresponding thioxotriazoles 6 and oxothiazolidines 7, respectively. All synthesized compounds were screened for their in vitro antibacterial activity against various Gram-positive and Gram-negative bacteria. Some test compounds were found to possess potent antibacterial activities. Compound, 7f, exhibited much higher potency than the reference standard ciprofloxacin, against both types of bacteria, particularly, Gram-positive organisms.