General Method for the Synthesis of 1,4-Disubstituted 5-Halo-1,2,3-triazoles

(E)-1-(5-Methyl-1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)-3-(naphthalen-2-yl)prop-2-en-1-one

A reaction of equimolar equivalents of 2-naphthaldehyde (1) and 1-(5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)ethan-1-one (2) in ethanolic sodium hydroxide at 20 °C for 4 h gave (E)-1-(5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)-3-(naphthalen-2-yl)prop-2-en-1-one (3) in 92% yield. Nuclear magnetic resonance spectroscopy and single-crystal X-ray diffraction were used to establish the structure of 3.

(Z)-2-(1-(5-Methyl-1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)ethylidene)-N-phenylhydrazine-1-carbothioamide

Reaction of equimolar equivalents of 1-(5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)ethan-1-one (1) and N-phenylhydrazinecarbothioamide (2) in boiling ethanol containing a catalytic amount of concentrated hydrochloric acid for 4 h gave (Z)-2-(1-(5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)ethylidene)-N-phenylhydrazine-1-carbothioamide (3) with 88% yield. The structure of 3 was established using single-crystal X-ray diffraction and magnetic resonance spectroscopy.

Synthesis and Structure Determination of 1-(4-Methoxyphenyl)-5-methyl-N’-(2-oxoindolin-3-ylidene)-1H-1,2,3-triazole-4-carbohydrazide

A reaction of equimolar equivalents of 1-(4-methoxyphenyl)-5-methyl-1H-1,2,3-triazole-4-carbohydrazide (1) and indoline-2,3-dione (2) in boiling ethanol for 4 h under acidic conditions gave 1-(4-methoxyphenyl)-5-methyl-N’-(2-oxoindolin-3-ylidene)-1H-1,2,3-triazole-4-carbohydrazide (3) in 88% yield. The structure of 3 was ascertained by NMR spectroscopy and single-crystal X-ray diffraction.

General Method of Synthesis of 5-(Het)arylamino-1,2,3-triazoles via Buchwald–Hartwig Reaction of 5-Amino- or 5-Halo-1,2,3-triazoles

An efficient access to the novel 5-(het)arylamino-1,2,3-triazole derivatives has been developed. The method is based on Buchwald–Hartwig cross-coupling reaction of 5-Amino or 5-Halo-1,2,3-triazoles with (het)aryl halides and amines, respectively. As result, it was found that palladium complex [(THP-Dipp)Pd(cinn)Cl] bearing expanded-ring N-heterocyclic carbene ligand is the most active catalyst for the process to afford the target molecules in high yields.

A general method of Suzuki–Miyaura cross-coupling of 4- and 5-halo-1,2,3-triazoles in water

A general method of the synthesis of 1,4,5-trisubstituted-1,2,3-triazoles by Suzuki–Miyaura cross-coupling from 4- and 5-halo-1,2,3-triazoles.