- Molybdate and silica sulfuric acids as heterogeneous alternatives for synthesis of gem-bisamides and bisurides from aldehydes and amides, carbamates, nitriles or urea
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Molybdate sulfuric acid (MSA) and silica sulfuric acid (SSA) has been prepared and used as efficient solid catalysts for the synthesis of gem-bisamides and bisurides via the one-pot three-component reaction of two moles of amides, nitriles, carbamates or urea with aldehydes. The catalytic efficiency of SSA, MSA, or H2SO4 98% per H+ sites as turnover number (TON), turnover frequency (TOF), and atomic economy (AE) was calculated and compared for quantitative evaluation of catalysts. The AE, TON, and TOF factors show the superiority of the SSA versus MSA and H 2SO4. Short reaction times, simple work-up, chemoselectivity, low loading, and reusability of solid acid catalysts are extra advantages than current methods reported in the literature with corrosive acidic catalysts.
- Tamaddon, Fatemeh,Kargar-Shooroki, Hossein,Jafari, Abbas Ali
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- One step process for preparing cross-linked poly-β-alanine microspheres from acrylamide and a copolymerisable polyfunctional compound
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A one-step process for preparing cross-linked poly-β-alanine as microspheres having narrow size distribution comprises polymerizing acrylamide with a polyfunctional compound copolymerizable with acrylamide (with the polyfunctional compound also acting as the cross-linking agent) in an organic solvent or a mixtured such solvents in the presence of an ionic polymerization initiator and a suspension agent. The resulting microspheres may be impregnated with a pharmaceutically or cosmetically active substance.
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