Investigation of antioxidant properties of some 6-(α-aminobenzyl)thiazolo[3,2-b]-1,2,4-triazole-5-ol compounds

Visible-light-mediated regioselective synthesis of novel thiazolo[3,2-b][1,2,4]triazoles: advantageous synthetic application of aqueous conditions

From a green chemistry perspective, sustainable irradiation as the power source and water as the solvent have certainly grabbed the attention of chemists in recent times because their use helps reduce the hazardous ecological footprints of organic synthesis. In the present work, we have established an efficient, straightforward and green protocol for the regioselective synthesis of novel functionalized thiazolo[3,2-b][1,2,4]triazoles. The visible-light-mediated catalyst-free reaction of diversely substituted α-bromodiketones, generated in situ by the reaction of NBS and 1,3-diketones, with 3-mercapto[1,2,4]triazoles under aqueous conditions afforded thiazolo[3,2-b][1,2,4]triazole derivatives in excellent yields. The structure of the regioisomer has been confirmed explicitly by heteronuclear 2D-NMR [(¹H-¹³C) HMBC, (¹H-¹³C) HMQC] spectroscopic and X-ray crystallographic studies. Radical initiating and trapping experiments supported the free radical mechanism for the cyclization.

Diastereoselective Synthesis of Spiro[Pyrrolo[2,1-B][1,3] Benzothiazole-3,5′-[1,3]Thiazolo[3,2-B][1,2,4]Triazol]-6′-Ones via Cycloaddition Reaction of Benzothiazolium Salts

The 1,3-dipolar cycloaddition reaction of (Z)-5-arylidene[1,3]thiazolo[3,2-b][1,2,4]triazol-6(5H)-one and azomethine ylide, which was generated in situ by the reaction of N-4-methoxyphenacylbenzothiazolium bromides and triethylamine, afforded novel 2-(aryl)-1-(4-methoxybenzoyl)-1,2-dihydrospiro[pyrrolo[2,1-b][1,3]benzothiazole-3,5′-[1,3]thiazolo[3,2-b][1,2,4]triazol]-6′-ones in moderate yields. The structures of all the products were characterised thoroughly by NMR, IR and HRMS spectroscopy together with X-ray crystallographic analysis.

The crystal structure of 4-allyl-5-benzyl-2,4-dihydro-3H-1,2,4-triazol-3-one, C12H13N3O

C12H13N3O, monoclinic, P21/c (no. 14), a = 11.0784(3) Å, b = 14.4910(4) Å, c = 7.1565(2) Å, β = 97.668(2)°, V = 1138.61(5) Å3, Z = 4, R gt (F) = 0.0432, wR ref (F 2 ) = 0.1328, T = 296 K.

Antimicrobial and antiurease activities of newly synthesized morpholine derivatives containing an azole nucleus

2-[6-(Morpholin-4-yl)pyridin-3-ylamino]acetohydrazide (4) was obtained starting from 6-morpholin-4-ylpyridin-3-amine (2) via the formation of ester (3) and then converted to the corresponding Schiff bases (5, 6) with the reaction with aromatic aldehydes. The carbothioamide (9), obtained from the reaction of hydrazide with phenylisothiocyanate, was converted to the corresponding 1,2,4-triazole (11) and 1,3,4-thiadiazole (12) derivatives by the treatment with NaOH or H2SO4, respectively. The cyclocondenzation of 9 with 4-chlorophenacyl bromide or ethyl bromoacetate produced the corresponding 1,3-thiazole (10) or 1,3-thiazolidine derivatives (13), respectively. Antimicrobial and antiurease activities of newly synthesized compounds were investigated. Some of them were found to be active on M. smegmatis, and they displayed activity toward C. albicans and S. cerevisiae in high concentration. Compound 10 proved to be the most potent showing an enzyme inhibition activity with an IC50 = 2.37 ± 0.19 μM.