Moderate and Efficient One-Pot Multicomponent Strategy to Perform a New Series of Fused 1,2,4-Triazolopyrimidine Derivatives Assisted by Lemon Juice and Grinding Technique

Abstract

Polyfused heterocyclic compounds have been performed by using lemon juice as active natural acid catalysis through one of the most important and famous reactions represented by the Biginelli reaction as a one-pot multicomponent reaction using only stirring at room temperature (25°C) as moderated circumstances. Substantially, the reaction started firstly by the action of hydrazine carbohydrazide (1) on the isophorone to achieve the corresponding hydrazone (2) in acidic media from glacial acetic acid, which then underwent intercyclization reaction via grinding technique for (20 minutes) with thiourea in basic media from NaOH (10%) to obtain 3-(2-isopheronyl hydrozonyl)-5-amino-1,2,4-triazole (3). Finally, the compound (3) proceeded through a one-pot Biginelli reaction with dimedone and substituted benzaldehyde in the presence of the catalytic amount of lemon juice as a natural acidic catalyst to achieve poly fused 1,2,4-triazole pyrimidine derivatives (4-6) in moderate and selective circumstances.