Synthesis, Spectroscopic and Thermal Characterization of Azido-1,2,4-triazoles: A Class of Heteroarenes with a High Nitrogen Content

• Published in: European Journal of Organic Chemistry Vol. 2012; no. 6; pp. 1195 - 1201
• Main Authors: Cardillo, Paolo, Dellavedova, Marco, Gigante, Lucia, Lunghi, Angelo, Pasturenzi, Christian, Salatelli, Elisabetta, Zanirato, Paolo
• Format: Book Review Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.02.2012; WILEY‐VCH Verlag; Wiley; Wiley-VCH
• Subjects: Ab initio calculations; ARC test; Azido-heteroaryls; Chemical reactivity; Chemistry; Chemistry, Organic; Density functional calculations; DSC ­analysis; Electronic structure; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; Kinetics and mechanisms; Organic chemistry; Physical Sciences; Preparations and properties; Reactivity and mechanisms; Science & Technology; Electronic structure; ENERGY; AZIDES; SUBSTITUENTS; ARC test; Azido-heteroaryls; Density functional calculations; DSC -analysis; Ab initio calculations; DERIVATIVES; SOLVENT; Nitrogen heterocycle; Ab initio method; Hartree Fock method; 1,2,4-Triazole derivative; Thermal reaction; Modeling; Optimization; Characterization; Carboxylic acid; Chemical reactivity; Chemical synthesis; Moller Plesset partition; Differential scanning calorimetry; DSC analysis; Organic azide; Thermal decomposition; Theoretical study; Guanidines; Tautomer; Reaction rate; Triazole derivatives; Density functional method; Kinetics; Spectrophotometry; Mass spectrometry
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.201101450

The syntheses of azido‐1,2,4‐triazoles 1–5 were carried out from triaminoguanidine hydrochloride and a carboxylic acid (formic, acetic, 2,2,2‐trifluoroacetic, 2‐benzylacetic, monochloroacetic acid) by a three‐step synthetic route and were analyzed by accelerating rate calorimetry (ARC). The thermal decomposition of 1–5 was studied theoretically by using CHETAH and T1 software, and experimentally by using DSC to obtain kinetic data. Numerical modelling and mass spectrometry were also performed to estimate the nature of the intrinsic molecular reactivity of 1–5 and the possible early stages of a self‐heating process. Complete optimization by using HF, B3LYP and MP2(full) methods at the 6‐31G* level were performed on significant tautomeric forms of the azido‐triazoles to confirm the electronic structures that were obtained by EI‐MS. We have synthesized azido‐1,2,4‐triazoles 1–5 from triaminoguanidine hydrochloride and a carboxylic acid by a three‐step route. The procedure has been optimized from a “green agreeability” point of view. The thermal decomposition of 1–5 has been investigated theoretically by using predictive software, and experimentally by using differential scanning calorimetry.