Dimethylcarbonate for eco-friendly methylation reactions.
Dimethylcarbonate (DMC), an environmentally friendly substitute for dimethylsulfate and methyl halides in methylation reactions, is a very selective reagent. Both under gas-liquid phase transfer catalysis (GL-PTC) and under batch conditions, with potassium carbonate as the catalyst, the reactions of DMC with methylene-active compounds (arylacetonitriles and arylacetoesters, aroxyacetonitriles and methyl aroxyacetates, benzylaryl- and alkylarylsulphones) produce monomethylated derivatives, with a selectivity not previously observed (i.e., >99%). The highly selective O-methylation of phenols and p-cresols by DMC is also attained by a new methodology using a continuous fed stirred tank reactor (CSTR) filled with a catalytic bed of polyethyleneglycol (PEG) and potassium carbonate.
Memoli
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Interuniversity, Consortium Chemistry for the Environment, Venice, Marghera, Italy.
Selva
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Tundo
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D002254:Carbonates / Q000737:chemistry; D002384:Catalysis; D002617:Chemical Industry; D004787:Environmental Pollution / Q000517:prevention & control*; D004867:Equipment Design; D005561:Formates / Q000737:chemistry*; D005740:Gases; D008745:Methylation; D010636:Phenols / Q000737:chemistry; D011188:Potassium / Q000737:chemistry
D002254:Carbonates; D005561:Formates; D005740:Gases; D010636:Phenols; C037593:potassium carbonate; C023025:methyl carbonate; D011188:Potassium