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Mechanism of 4‐methyl‐1,2,4‐triazol‐3‐thione reaction with formaldehyde
Author(s) -
Wujec Monika,
Paneth Piotr
Publication year - 2008
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.1324
Subject(s) - chemistry , tautomer , formaldehyde , reactivity (psychology) , sulfur , nucleophile , hydroxymethyl , medicinal chemistry , computational chemistry , reaction mechanism , thiol , nucleophilic substitution , photochemistry , stereochemistry , organic chemistry , catalysis , medicine , alternative medicine , pathology
We have recently described theoretically the mechanism of the reaction between 4‐methyl‐1,2,4‐triazol‐3‐thiol and formaldehyde that leads to the N‐ substituted product, N 1 ‐hydroxymethyl‐4‐methyl‐1,2,4‐triazol‐3‐thione. New experimental findings indicate that the thione tautomeric form in reaction with formaldehyde also yields this product. This observation could not be explained on the basis of previous calculations, which predicted that the thione tautomer undergoes nucleophilic substitution at the sulfur atom, leading to the S‐ substituted product. We present theoretical explanation of the observed reactivity. We show that under experimental conditions this reaction proceeds with the intervention of the anionic form of the triazole with the Gibbs free energy of activation of only 1.8 kcal/mol. Copyright © 2008 John Wiley & Sons, Ltd.