Facile and green synthesis of a series of dihydro-[1,2,4]triazolo[1,5-a]pyrimidine scaffolds
Document Type
Article
Publication Date
1-1-2020
Abstract
This work presents a new catalytic application of 4,4'-trimethylenedipiperidine for the efficient synthesis of a series of dihydro-[1,2,4] triazolo[1,5-a]pyrimidines. According to the principles of green chemistry, the reaction was performed (a) in a solvent mixture comprised of water and ethanol (1:1 v/v) at reflux temperature and (b) solvent-free grinding in a mortar by a pestle. The organocatalyst could be reused up to 10 runs, and no reduction of catalytic activity was detected. A variety of substituted dihydro-[1,2,4] triazolo[1,5-a]pyrimidines were obtained in good to excellent yields under eco-friendly conditions. 4,4'-Trimethylenedipiperidine is commercially available and easy to handle, and it also shows high thermal stability and good solubility in water. This work revealed that this organocatalyst, a hydrogen bond donor to active carbonyl groups and simultaneously a Lewis base through the nitrogen atom of second piperidine moiety, could play a vital role in the promotion of the one-pot multi-component reactions. The main merits of the current methodology include short reaction time, wide substrate scope, use of a metal-free catalyst and green solvents, and simple work-up process. Furthermore, this organocatalyst can be an alternative to piperidine for organic transformations. © 2020, Canadian Science Publishing. All rights reserved.
Keywords
Annulation, Heterocycles, One-pot synthesis, Organocatalyst, Three-component reaction
Divisions
nanotechnology
Funders
High Impact Research Grant (NANOCAT RU001-2019) for Scientific Research from the University of Malaya, Malaysia
Publication Title
Canadian Journal of Chemistry-Revue Canadienne De Chimie
Volume
98
Issue
10
Publisher
Canadian Journal of Chemistry-Revue Canadienne De Chimie