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Publikace detail

A safe and efficient route for the preparation of nitro, dinitro, and trinitrophenyl chloroformates
Rok: 2013
Druh publikace: ostatní - přednáška nebo poster
Strana od-do: nestránkováno
Tituly:
Jazyk Název Abstrakt Klíčová slova
eng A safe and efficient route for the preparation of nitro, dinitro, and trinitrophenyl chloroformates One group of the currently manufactured specialties of phosgene chemistry are mono-, di- and trinitrophenyl chloroformates. These esters containing good leaving groups are particularly used for activation of amino and hydroxy groups in syntheses1 of the carbonates, carbamates and ureas that find applications in agrochemistry, medicinal chemistry or nanochemistry. A safe and simple method has been developed for synthesis of chloroformates derived from 2-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol, 2,4,6-trinitrophenol and pentafluorophenol, the yields being in the range of 72-96 %. The method is based on a heterogeneous reaction of the substituted phenol with phosgene dissolved in dichloromethane catalyzed with solid anhydrous potassium carbonate. The synthesis of 2,4,6-trinitrophenyl chloroformate takes place only in the presence of a phase-transfer catalyst, in this case the easily recoverable ?,?-dimethoxy poly(ethylene glycol) (PEG; M = 2 kDa). The only waste products of the suggested synthesis of the mentioned esters are sodium chloride and potassium chloride. The method markedly reduces the explosion risk connected with drying and handling of salts of mono-, di- and trinitrophenols and is much more environment-friendly than the currently used methods. preparation; nitrophenyl chloroformates