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The present work emphasizes catalyst‐free 2,4,5‐tri‐ and 1,2,4,5‐tetra substituted imidazole synthesis using diversified aldehydes with benzil, ammonium acetate, or amines. Ammonium acetate plays a vital role as a reactant catalyst by dissociating into acetic acid to afford imine and diamine formation to ascertain the 2,4,5‐tri‐ and 1,2,4,5‐tetra substituted imidazoles. The key advantages of the current approach are efficient, greener, eco‐friendly, and facile, with moderate to excellent yield in shorter reaction time at the temperature of 80°C. Ethanol:water as a solvent makes the reaction process eco‐friendly. Overall, the described approach offers a promising route for the efficient and sustainable synthesis of substituted imidazoles, which have a wide range of applications in various fields, including pharmaceuticals, agrochemicals, and materials science. [ABSTRACT FROM AUTHOR]

This report describes an efficient method for one-pot, three-component coupling of aldehydes, β-ketoesters/β-diketone, and urea/thiourea catalyzed by N-(phenylsulfonyl)benzene sulfonamide (NPBSA) as efficient organocatalyst to afford the corresponding 3,4-dihydropyrimidine-2(1H)-ones/thiones via Biginelli condensation. Novel catalyst, high yields, quick reaction time, solvent-free environment, simple workup, and the ability to tolerate a variety of functional groups are some of the advantages of the current method, providing economic and environmental benefits. The present work also includes the synthesis of active pharmaceutical ingredient Piperasterol as application of the method. [ABSTRACT FROM AUTHOR]

The catalyst was stored in glass bottle under nitrogen at 2-8 °C and used under a nitrogen atmosphere. The catalyst has been characterized by FTIR, XRD, SEM, and EDAX.[30] General procedure for the synthesis of N,N'-di(aryl/alkyl)substituted formamidines A mixture of amine (2 mmol) and triethyl orthoformate (1.5 mmol) was mixed with 10 wt % aluminized polyborate catalyst under a nitrogen atmosphere and the resulting mixture was stirred in an oil bath preheated to 60 °C. For our preliminary experiments, triethyl orthoformate (1.5 mmol) and aniline (2 mmol) were directly reacted under solvent-free conditions to afford ( I E i ) I N,N' i -diphenylformimidamide. [Extracted from the article]