New protocols for the synthesis of 5-amino-7-(4-phenyl)-4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylate esters using an efficient additive
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Date
2020
Journal Title
Journal ISSN
Volume Title
Publisher
TUBITAK
Abstract
This work introduces a new additive named 4,4’-trimethylenedipiperidine for the practical and ecofriendly
preparation of ethyl 5-amino-7-(4-phenyl)-4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylate derivatives. This
chemical is commercially available and easy to handle. It also possesses a low melting point and a broad liquid range
temperature, high thermal stability, and good solubility in water. Based on green chemistry principles, the reaction
was performed in a) a mixture of green solvents i.e. water and ethanol (1:1 v/v) at reflux temperature, and b) the
additive was liquefied at 65 ◦ C and the reaction was conducted in the liquid state of the additive. High yields of
the desired triazolo-pyrimidines were obtained under both aforementioned conditions. Our results demonstrated that
this additive, containing 2 Lewis base sites and able to act as an acceptor-donor hydrogen bonding group, is a novel
and efficient alternative to piperidine, owing to its unique properties such as its reduced toxicity, nonflammable nature,
nonvolatile state, broad liquid range temperature, high thermal stability, and ability to be safely handled. Furthermore,
this additive could be completely recovered and exhibited high recyclability without any change in its chemical structure
and no significant reduction in its activity.
Description
Keywords
Organic catalysis, Lewis base, Heterocycles, Three-component reactions, Sustainable chemistry
Citation
Titinchi, S. et al. (2020). New protocols for the synthesis of 5-amino-7-(4-phenyl)-4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylate esters using an efficient additive. Turkish Journal of Chemistry ,44(4), 1100-1109