An Efficient and Environmentally Friendly Procedure for the Synthesis of Some Novel 8-Benzylidene-4-phenyl-3,4,5,6,7,8-hexahydro-1H-quinazolin-2-ones/thiones using Tetrabutylammonium Hexatungstate as a Reusable Heterogeneous Catalyst under Solvent-Free Conditions

Abstract

An efficient method for the preparation of 8-benzylidene-4-phenyl-3,4,5,6,7,8-hexahydro-1H-quinazolin-2-ones/thiones from the reaction of aromatic aldehydes with cyclohexanone and urea or thiourea in the presence of Tetrabutylammonium hexatungstate, [TBA]2[W6O19], as an efficient, inexpensive catalyst under thermal and solvent-free conditions has been developed. Good yields, short reaction times, straightforward workup, reusability of the catalyst, and green conditions are the most obvious advantages of this procedure.

Preparation of skeletally diverse quinazoline-2,4(1H,3H)-diones using Na2SiO3/SnFe2O4 catalytic system through a four-component reaction

“…Heterocycles bearing quinazoline core structures played a significant role in research fields such as chemistry, drug development and biological investigations (Ghashang, 2012;Ghashang et al, 2013Ghashang et al, , 2015. Quinazoline and especially quinazoline-2,4(1H,3H)-dione derivatives have attracted significant attention due to diverse pharmacological activities such as anti-proliferative activities against HCT-116 and MCF-7 cell lines (Hei et al, 2016), anti-proliferative activity in LNCaP and prostate cancer cell lines (Maestri et al, 2017), isoform-selective PI3K-α inhibition (Yadav et al, 2016), PARP-1/2 inhibition activity (Zhou et al, 2018).…”

Ethyl (E)-4-(2,4-Dimethoxyphenyl)-6-(2,4-dimethoxystyryl)-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate

“…Although this reaction normally produces DHPM derivatives, there are similar reactions, usually called Biginelli-type reactions, that produce different pyrimidine derivatives, such as spiropyrimidinone [3,4] and arylidinepyrimidinone [5][6][7][8][9][10][11].…”

“…Despite the similarity of its reaction pattern to the Biginelli-type reaction producing arylidenepyrimidinone, there is a difference in the carbonyl component used. The aforementioned Biginelli-type reaction uses a cyclic mono carbonyl component that has two kinds of acidic C-H with equivalent reactivity, such as cyclopentanone [5][6][7][8][9][10], cyclohexanone [9][10][11] and cyclooctanone [9], so that it yields a bicyclic arylidenepyrimidinone. Interestingly, in our experiment, we used an acyclic 1,3-dicarbonyl component that possessed two acidic C-H moieties with different reactivities, namely ethyl acetoacetate.…”