The Acetylation of 3‐Amino‐1,2,4‐triazole

Acetylation of 5-Amino-1H-[1,2,4]triazole Revisited

“…A suspension of 5-amino-1 H -[1,2,4]triazole (1.26 g, 15 mmol) in acetic anhydride (15 mL) was stirred for 20 h, the reaction mixture evaporated, and the residue crystallized from acetonitrile (4 mL) to give colorless crystals (1.28 g, 51%): mp 195.91 °C [Lit. 190−191 °C (); 38%, 191−193 °C (); 48%, 190 °C ()]; t R 6.21, 92.00% purity; 1 H NMR δ 10.760 (s, 1H, NH), 9.108 (s, 1H, N−CH) ( , ), 2.582 (s, 3H, CH 3 -ring), 2.073 (s, 3H, CH 3 ).…”

“…Water (50 mL) was added to the residue, and the suspension was stirred for 24 h. The precipitate was filtered off to give colorless crystals (1.12 g, 89%): mp 298.94 °C [Lit. 295−300 °C (); 100%, 288 °C (); 95%, 287−288 °C ()]; t R 2.82, 100.00% purity; 1 H NMR δ 13.283 (s, 1H, NH-ring), 11.105 (s, 1H, CONH), 7.841 (s, 1H, N−CH) ( , ), 2.073 (s, 3H, CH 3 ). Evidence for the tautomeric proton position of the compound is given in Table .…”

“…Studies on the acetylation of 5-amino-1 H -[1,2,4]triazole (AT) have shown ( Figure ) that 1 equiv of acetyl chloride yields an annular N-acetylated product ( − ). This contains the CO band at 1732 cm -1 in the IR (KBr) spectrum (), and its annular proton chemical shift is 7.57 δ in the 1 H NMR [(CD 3 ) 2 SO] spectrum ( , ), which would indicate the structure of 1-acetyl-5-amino-1 H -[1,2,4]triazole [AT(Ac); 1 ] and not that of 1-acetyl-3-amino-1 H -[1,2,4]triazole [(AT(Ac‘); 2 ] as has been incorrectly ascribed (). 1-Acetyl-5-amino-1 H -[1,2,4]triazole ( 1 ) in the fused state ( , ) or in concentrated solutions () at higher temperatures undergoes an intermolecular () transacetylation to 5-(acetylamino)-1 H -[1,2,4]triazole (Ac-AT; 3 ).…”

“…1-Acetyl-5-amino-1 H -[1,2,4]triazole ( 1 ) in the fused state ( , ) or in concentrated solutions () at higher temperatures undergoes an intermolecular () transacetylation to 5-(acetylamino)-1 H -[1,2,4]triazole (Ac-AT; 3 ). Both monoacetyl isomers 1 and 3 , when treated with the second equivalent of acetyl chloride, are converted to 1-acetyl-3-(acetylamino)-1 H -[1,2,4]triazole [Ac-AT(Ac ‘ ); 4 ] ( , ). The same diacetyl compound was also obtained from 5-amino-1 H -[1,2,4]triazole with neat acetic anhydride at reflux ().…”

Synthesis and growth regulatory activity of pyrazolesulfanyl‐ and isoxazolesulfanyl‐1H‐[1,2,4]triazoles and their azinyl derivatives

“…In the case of compounds 4 , the basic question is at which position of triazole ring the heterylation reaction occurs. Value of 9.0–9.1 ppm for H‐5 in 1 H NMR spectra allows excluding 2‐N substitution [28], but do not make a choice between 1‐N and 4‐N substitutions. In some cases, by means of mass spectra a substitution position in triazole cycle can be established [29–31].…”