Study of the Regioselectivity of the N-alkylation Reaction of 1H-1,2,4-Triazole with an O-tosyl Derivative, Using Two-Dimensional NMR Spectroscopy

Younas Aouine; Salaheddine Boukhssas; Anouar Alami; Hassane Faraj; Abdelilah El Hallaoui

Younas Aouine Organic Chemistry Laboratory (LCO), Faculty of Sciences Dhar El Mahraz, Sidi Mohammed Ben Abdellah University, P.B. 2626, Fez 30000, Morocco and Department of Chemistry, Faculty of Sciences, Ibn Zohr University, P.B. 8106, Cit� Dakhla, Agadir 80060, Morocco.
Salaheddine Boukhssas Doctoral Training �Bioactive Molecules, Health and Biotechnology�, Faculty of Sciences Dhar El Mahraz, Center of Doctoral Studies �Sciences and Technology�, Sidi Mohamed Ben Abdellah University, P.B. 2626, Fez 30000, Morocco and Organic Chemistry Laboratory (LCO), Faculty of Sciences Dhar El Mahraz, Sidi Mohammed Ben Abdellah University, P.B. 2626, Fez 30000, Morocco.
Anouar Alami Organic Chemistry Laboratory (LCO), Faculty of Sciences Dhar El Mahraz, Sidi Mohammed Ben Abdellah University, P.B. 2626, Fez 30000, Morocco.
Hassane Faraj Organic Chemistry Laboratory (LCO), Faculty of Sciences Dhar El Mahraz, Sidi Mohammed Ben Abdellah University, P.B. 2626, Fez 30000, Morocco.
Abdelilah El Hallaoui Organic Chemistry Laboratory (LCO), Faculty of Sciences Dhar El Mahraz, Sidi Mohammed Ben Abdellah University, P.B. 2626, Fez 30000, Morocco.

Keywords: Oxazoline, 1H-1,2,4-triazole, ?-aminoalcohol, ?-amino acid, 2D heteronuclear NMR experiments

Abstract

The alkylation reaction of 1H-1,2,4-triazole with (4-methyl-2-phenyl-4,5-dihydrooxazol-4-yl)methyl-4-methylbenzenesulfonate in presence of K₂CO₃ as base and a catalytic amount of tetrabutylammonium bromide in N,N-dimethylformamide, followed by an oxazoline ring-opening reaction in an acidic medium, and protection of amine function, leads normally to obtain two regioisomers of N-protected ?-aminoalcohols with prevalence of the N₁-isomer. After purification by column chromatography of the crude reaction product, only a single product is obtained in 97% yield. Hence, there is need of its identification by spectroscopic study.