Due to their high synthetic efficiency, multi-component reactions (MCRs) have shown to be extraordinarily effective at producing compounds in a single synthetic operation. The chromeno[2,3-d] pyrimidine moieties represent important building blocks in synthetic bioactive compounds. The reaction of barbituric acid, aldehydes, and cyclohexane-1,3-diones in the presence of zinc acetate (5 mol%) under neat conditions at 70 0C, yielded a facile and one-pot synthesis of corresponding chromeno[2,3-d]pyrimidineones. Thirteen compounds containing neutral, withdrawing and electron donating groups (H, NO₂, -CN, -Cl; -OH, -CH₃ and -OCH₃) were synthesized in good, isolated yields ranging from 78-91%. The successful involvement of o-, m-, and p- substituted nitro benzaldehydes suggested that steric hindrance had no effect. All of the synthesized compounds are well-known, and this process is unique in that it makes use of zinc acetate, an accessible, low-cost Lewis acid catalyst.

In this communication, condensation from different aromatic, aliphatic and heteroaromatic aldehydes, hydroxyl amine, and sodium azide in toluene reflux was used to produce electronically and structurally distinct tetrazoles with a range of yields 5-94%. Zn(OAc)2•2H2O (10 mol%) was used as a catalyst in the synthesis, which was eco-friendly, readily available, and affordable. The IR, NMR, and mass spectral studies were utilized in order to carry out a comprehensive characterization for all the 5-aryl tetrazole derivatives. This approach contributes to the current chemical synthesis of 5-substituted-1H-tetrazoles in an appealing and convenient manner thanks to its quick reaction times, good to exceptional yields, safe process, and straightforward workup.

In this study, the selective oximation of structurally diverse aromatic aldehydes (versus ketones) to the corresponding aldoxime derivatives was investigated using the combination system of NH₂OH.HCl and bisthiourea complexes of cobalt, nickel, copper and zinc chlorides, M^II(tu)₂Cl₂, in a mixture of CH₃CN‒H₂O (1:1 mL). All reactions were carried out successfully at room temperature within the immediate time up to 130 min giving the products in high yields. Investigation of the results exhibited that the applied bis-thiourea metal complexes show the catalytic activity in order of Co(tu)₂Cl₂₂Cl₂₂Cl₂₂Cl₂ in their oximation reactions.

Selective oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones was achieved efficiently using K2S2O8/activated charcoal system. All reactions were carried out at solvent?free conditions (40?45 ?C) within 15?60 min to give the products in high to excellent yields.

Imines of six new quinolin-5-ylamine derivatives 3(a-c) and 5(a-c) were synthesized by the reaction of quinolin-5-ylamine (1) with different aldehydes 2(a-c) and ketones 4(a-c). The chemical structures of the compounds were confirmed by UV-visible, FT-IR and 1H NMR spectral study. New compounds were screened for the antioxidant activity by DPPH (2,2-diphenyl-1-picrylhydrazyl) method. Butylated Hydroxytoluene (BHT) was used as standard. All the compounds showed DPPH radical scavenging activity, where compound 3c was the best radical scavenger.

2,4,5-Trisubstituted imidazoles have many pharmaceutical properties and can be prepared via reaction of 1, 2-diketones with aldehydes in the presence of an acidic catalyst. In this work, we have prepared 2,4,5-trisubstituted imidazoles in the presence of trichloromelamine as a source of positive chlorine. Short reaction times, high yield, simplicity of operation and easy work-up are some advantages of this method.