Highly Selective Alkylation of 5-Amino-1-methyl-1H-1,2,4-triazole with 1-(1-Chloroalkyl)pyridinium Chlorides under Formation of Novel Geminal Bis(heteroarylium) Salts: A Combined Experimental/MO-Theoretical Study
✍ Scribed by Anders, Ernst ;Wermann, Kurt ;Wiedel, Bernd ;Eynde, Jean-Jacques Vanden
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 795 KB
- Volume
- 1997
- Category
- Article
- ISSN
- 0947-3440
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✦ Synopsis
Abstract
1‐[(5‐Amino‐1‐methyl‐1__H__‐1,2,4‐triazol‐4‐ylium)(alkyl/aryl)‐methyl]pyridinium dichlorides 3a–h [geminal bis(heteroarylium) salts] were synthesized in high yield from 5‐amino‐1‐methyl‐1__H__‐1,2,4‐triazole (6a) and the 1‐[(alkyl/aryl)chloromethyl]pyridinium chlorides 1a–h under mild, neutral conditions. Analogous reactions of 1a and 1d with the isomeric 3‐amino‐1‐methyl‐1__H__‐1,2,4‐triazole (6b), carried out to support the spectroscopic analysis of the alkylation products 3a–h, likewise show exclusive alkylation at the N‐4 atom of the 1__H__‐1,2,4‐triazole ring with formation of the isomeric 1‐[(3‐amino‐1‐methyl‐1__H__‐1,2,4‐triazol‐4‐ylium)arylmethyl]pyridinium dichlorides 4a and 4d, respectively. Semiempirical MO and ab initio methods have been applied to predict the relative energies of isomers of 6, the activation barriers of the reaction of electrophiles with 6, and the relative energies of some product salts.