146 research outputs found
Microwave assisted solvent free synthesis of 1,3-diphenylpropenones
<p>Abstract</p> <p>Background</p> <p>1,3-Diphenylpropenones (chalcones) are well known for their diverse array of bioactivities. Hydroxyl group substituted chalcones are the main precursor in the synthesis of flavonoids. Till date various methods have been developed for the synthesis of these very interesting molecules. Continuing our efforts for the development of simple, eco-friendly and cost-effective methodologies, we report here a solvent free condensation of aryl ketones and aldehydes using iodine impregnated alumina under microwave activation. This new protocol has been applied to a variety of substituted aryl carbonyls with excellent yield of substituted 1,3-diphenylpropenones.</p> <p>Results</p> <p>Differently substituted chalcones were synthesized using iodine impregnated neutral alumina as catalyst in 79-95% yield in less than 2 minutes time under microwave activation without using any solvent. The reaction was studied under different catalytic conditions and it was found that molecular iodine supported over neutral alumina gives the best yield. The otherwise difficult single step condensation of hydroxy substituted aryl carbonyls is an attractive feature of this protocol to obtain polyhydroxychalcones in excellent yields. In order to find out the general applicability of this new endeavor it was successfully applied for the synthesis of 15 different chalcones including highly bioactive prenylated hydroxychalcone xanthohumol.</p> <p>Conclusion</p> <p>A new, simple and solvent free method was developed for the synthesis of substituted chalcones in environmentally benign way. The mild reaction conditions, easy work-up, clean reaction profiles render this approach as an interesting alternative to the existing methods.</p
Nucleophilic Displacements in Supercritical Carbon Dioxide Under Phase-Transfer Catalysis Conditions. II. Effect of Pressure and Kinetics
A Simple, One-Pot and Phosphine-Free Procedure for Thiocyanation of Alcohols Using N-(p-toluenesulfonyl) Imidazole (TsIm)
4-Aminophenyl Diphenylphosphinite (APDPP) as a Heterogeneous and Acid Scavenger Reagent for Thiocyantion or Isothiocyanation of Alcohols and Protected Alcohols
Heterogeneous Thiocyanation of Benzylic Alcohols and Silyl and THP Ethers, and Deprotection of Silyl and THP-Ethers by [PCl 3-n
Cyanuric chloride/dimethylformamide promoted one-pot conversion of primary alcohols into alkyl thiocyanates
Green preparation of disulfides from corresponding thiols by poly(4-vinylpyridinium nitrate) as recoverable and new polymeric reagent
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