In this research, the preparation, characterization and catalytic application of a novel 1,3,5-tris(2-hydroxyethyl)isocyanurate functionalized graphene oxide (GO–THEIC) nanomaterial are described. The GO/THEIC nanomaterial was characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and thermal gravimetric analysis (TGA) techniques. The catalytic application of the GO–THEIC nanocatalyst was then investigated in the Biginelli condensation of different aldehydes with alkylacetoacetates and urea or thiourea under solvent-free conditions and at a moderate temperature. Moreover, the significant advantages of this procedure are the stability and reusability of the catalyst, low loading of the catalyst, avoiding the use of toxic transition metals, short reaction times, high to excellent yields, and easy separation and purification of the products.

1,3,5-Tris(2-hydroxyethyl)isocyanurate functionalized graphene oxide: a novel and efficient nanocatalyst for the one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones

A library of dihydropyrimidinones was synthesized via a “one-pot” three component Biginelli reaction using different aldehydes in combination with β-dicarbonyl compounds and urea. Selected 2-thiooxo and 2-imino analogs were also obtained with the Biginelli reaction from thiourea and guanidine hydrochloride, respectively. The products were screened in vitro for their β-secretase inhibitory activity. The majority of the compounds resulted to be active, with IC50 in the range 100 nM–50 μM.

/pdf/one-pot-synthesis-of-micromolar-bace-1-inhibitors-based-on-3kvtp07wlb.pdf

One Pot Synthesis of Micromolar BACE-1 Inhibitors Based on the Dihydropyrimidinone Scaffold and Their Thia and Imino Analogues

Firstly, triarylmethanes bearing formyl groups (TRAM-CHOs) have been synthesized by the reaction of arenes with aromatic dialdehydes catalyzed by sulfuric acid immobilized on SiO2 under solvent-free grinding conditions in good yields and short grinding time. Secondly, condensation of TRAM-CHOs with several arenes proceeded rapidly within a few minutes to afford the new corresponding mixed-bistriarylmethanes in excellent yields. TRAM-CHOs were also found to be valuable precursors for the Biginelli reaction to synthesize a variety of 3,4-dihydropyrimidin-2(1H)-one-triarylmethane hybrid derivatives.

Synthesis of new mixed-bistriarylmethanes and novel 3,4-dihydropyrimidin-2(1H)one derivatives

Tetrabutyl phosphonium sulfate ([TBP]2SO4), as novel room-temperature ionic liquid (RTIL), was synthesized by a simple cost-effective method, characterized by 1H, 13C, 31P NMR and FT-IR spectrophotometry. The newly prepared catalyst was used as an efficient catalyst in some four multicomponent reactions (4MCRs) e. g., to synthesis pyridazino[1,2-a]indazole, indazolo[2,1-b]phthalazine and pyrazolo[1,2-b]phthalazine. This green method has several advantages such as short reaction time, using simple methods to prepare catalysts and products, easy operation and high efficiency of products. In addition, the catalyst can be easily recovered and reused several times with reduced average activity.

[TBP]2SO4 ionic liquid catalyst for 4MCR of pyridazinoindazole, indazolophthalazine and pyrazolophthalazine derivatives

/pdf/three-component-coupling-green-synthesis-of-3-4-1laaniu0bd.pdf

Three Component Coupling Green synthesis of 3, 4 dihydrtopyrimidinone derivatives under solvent free conditions by Biginelli reactions.

A new method for the synthesis of 1-methylimidazolium
trifluoroacetate ([Hmi]Tfa), a protic ionic liquid (PIL), under
ultrasonic irradiation has been developed. In addition, the product [Hmi]Tfa
was successfully employed as solvent and catalyst in Biginelli reaction to
prepare 3,4-dihydropyrimidinones (DHPMs) in high yield under mild reaction conditions.

https://file.scirp.org/pdf/GSC_2013112216182542.pdf

New Method for the Synthesis of 1-Methylimidazolium Trifluoroacetate and Its Application in Biginelli Reaction

A simple, efficient, and environmentally-friendly process has been developed for the synthesis of L-proline triflate ionic liquid (L-ProTfO) from L-proline and triflic acid using ultrasound irradiation. The combination of Lproline triflate ionic liquid technology with microwave energy represents an attractive and rapid alternative to the conventional acid-base-catalyzed thermal process. The current method has several advantages, including high yield, short reaction time, and work-up simplicity. In addition, the L-proline triflate ionic liquid could be recycled and reused four times without a noticeable decrease in catalytic activity.

/pdf/an-efficient-and-recyclable-l-proline-triflate-ionic-liquid-30408xeg6d.pdf

An efficient and recyclable L-proline triflate ionic liquid catalyst for one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones via the multi-component Biginelli reaction

Khan Manh Hua

Papers

New Method for the Synthesis of 1-Methylimidazolium Trifluoroacetate and Its Application in Biginelli Reaction

An efficient and recyclable L-proline triflate ionic liquid catalyst for one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones via the multi-component Biginelli reaction