decatungstodivanadogermanic acid (h6gew10v2o40.22h2o) was used as a green heterogeneous catalyst for the synthesis of 3,4-dihydropyrimidin-2-(1h)-ones from one-pot three-component cyclocondensation reaction of a β-ketoester, an aldehyde and urea/thiourea under solvent-free conditions is reported. this method provides an efficient and much improved modification of the original biginelli reaction...

A novel synthesis of Iimidazo[1,2-c]quinazoline-5(6H)-thione framework was developed through a three-step reaction starting from benzil. The resulting (2-nitrophenyl)-4,5-diphenyl-1H-imidazole  from the reaction of benzil and different 2-nitrobenzaldehyde, reduction of nitro group and then cyclization reaction with carbon disulfide (CS2). All steps were carried out under easy and user-friendly ...

The structure of 1-methyl-2-(prop-2-en-1-ylsulfan-yl)-1H-imidazol-3-ium bromide, C7H11N2S(+)·Br(-), has monoclinic (P21/c) symmetry. In the crystal, the components are linked by N-H⋯Br and C-H⋯Br hydrogen bonds. The crystal structure of the title compound undeniably proves that methimazole reacts through the thione tautomer, rather than the thiol tautomer in this system.

Three diazoles namely 5-methyl-1,3,4-oxadiazole -2(3H)-thione, 5-methyl-1,3,4-thiadiazol-2(3H)-thione and 4-amino-5-methyl-2H-1,2,4-triazole-3-thiol were synthesized from acetic acid or ethyl acetate. Seco-acyclo-N-nucleoside analogous was by condensation of 1,3-benzylidine-glyceryl-2-tosylate with the three diazoles. Structural proof based upon IR, 1H-NMR, 13C-NMR spectroscopy MS measurements....

Alkali and alkaline earth metals hydrogen sulfate catalyzed the one-pot three component condensation reactions of aldehydes, 1,3-dicarbonyl compounds and urea or thiourea under solvent-free conditions leading to 3,4-dihydropyrimidin-2(1H)-ones in high yields at 80 °C. Our results showed that Biginelli reaction not only is pH dependent, but the cation of catalyst plays an importan...

An improved, simple, and facile synthesis of 3,4-dihydropyrimidin-2(1H)-ones by employing three-component, one-pot condensation reaction of β-keto ester, aromatic aldehydes, and urea or N-methylurea using LaCl3/ClCH2COOH as an inexpensive and green chemistry catalyst system under solvent-free conditions described. Compared with the classicalBiginelli reaction conditions, this method has the adv...

In this study, an efficient and green process for the synthesis of dihydropyrimidin-2(1H)-ones from aromatic benzaldehydes, ethyl acetoacetate and urea using Al-MCM-41 as heterogeneous catalyst and microreactor under solvent-free conditions has been developed. The advantages of this method are easy work-up procedure, regeneration of the catalyst, clean and neutral reaction conditions.