A solution of structural ambiguity: s‐Triazolo[1,5‐a] – and s‐triazolo[4.3‐a] pyrimidines
- 1 December 1975
- journal article
- research article
- Published by Wiley in Journal of Heterocyclic Chemistry
- Vol. 12 (6) , 1187-1190
- https://doi.org/10.1002/jhet.5570120619
Abstract
The condensation of 3‐amino‐5‐benzylthio‐s‐triazole (2) with acetylacetone in refluxing acetic acid has been reported to have given 3‐benzylthio‐5,7‐dimethyl‐s‐triazolo[4,3‐a]pyrimidine (3). However, it has now been established, with the aid of 13C spectra and a modification of the original synthetic work, that only 2‐benzylthio‐5,7‐dimethyl‐s‐triazolo[1,5‐a]pyrimidine (4) can be obtained by this method of condensation. The erroneously reported, but previously unknown 6 was synthesized and its structure and that of 4 was firmly established by ir, uv, pmr,13 C nmr, tlc and mixed melting point data. The correct structures of 3‐mercapto‐5,7‐dimethyl‐s‐triazolo‐[4,3‐a]pyrimidine (5) and 2‐mercapto‐5,7‐dimethyl‐s‐triazolo[1,5‐a]pyrimidine (6) were also established and the facile rearrangement of 5 to 6 was demonstrated.This publication has 15 references indexed in Scilit:
- Syntheses of s-Triazolo [4, 3-a] Pyrimidine DerivativesAgricultural and Biological Chemistry, 1973
- Heterocyclic SystemsPublished by Elsevier ,1972
- 1,2,4‐Triazoles. XXV. The effect of pyridine substitution on the isomerization of s‐Triazolo[4,3‐a] pyridines into s‐Triazolo[1,5‐a] pyridinesJournal of Heterocyclic Chemistry, 1970
- 3‐Amino‐s‐triazolo [4,3‐a]pyridine aus 2‐Halogenpyridinen und ThiosemicarbazidZeitschrift für Chemie, 1970
- 1,2,4-Triazoles. XIV. Reactions of the s-Triazolo[4,3-a]pyridine Ring System1a,bThe Journal of Organic Chemistry, 1966
- s-TriazolopyrazinesJournal of the Chemical Society C: Organic, 1966
- 1080. S-triazolopyrimidines. Part I. Synthesis as potential therapeutic agentsJournal of the Chemical Society, 1963
- 692. Heterocyclic compounds from urea derivatives. Part I. A new synthesis of 3-amino-5-mercapto(and -hydroxy)-1,2,4-triazolesJournal of the Chemical Society, 1960
- 364. The structure of certain polyazaindenes. Part VI. The structure of some products obtained from 3-amino-1,2,4-triazoles with acetylacetone and ethyl acetoacetateJournal of the Chemical Society, 1960
- 915. Pyrimidines. Part IV. Experiments on the synthesis of pyrimidine and 4 : 6-dimethylpyrimidineJournal of the Chemical Society, 1952