- A safe and efficient route for the preparation of nitro-, dinitro-, and trinitrophenyl chloroformates
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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 recovered α,ω-dimethoxy poly(ethylene glycol) (PEG; M = 2kDa). 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 environmentally friendly than the currently used methods. Copyright
- Sedlak, Milos,Pejchal, Vladimir,Imramovsky, Ales,Hanusek, Jiri
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supporting information
p. 2365 - 2369
(2013/07/26)
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- Studies on Synthesis and Anticancer Activity of Selected N-(2-Fluoroethyl)-N-nitrosoureas
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An activated carbamate, 2-nitrophenyl (2-fluoroethyl)nitrosocarbamate (3), was used to advantage in the synthesis of the water-soluble (2-fluoroethyl)nitrosoureas 6a-d from 2-aminoethanol, (1α,2β,3α)-2-amino-1,3-cyclohexanediol, cis-2-hydroxycyclohexanol, and 2-amino-2-deoxy-D-glucose.In a variation of this method, 2,4,5-trichlorophenyl (2-fluoroethyl)carbamate (4) was used to prepare the urea from which the essentially water-insoluble N'-(2,6-dioxo-3-piperidinyl)-N-(2-fluoroethyl)-N-nitrosourea (6e) was derived.The anticancer activity of these nitrosoureas was determined against the murine tumors B16 melanoma and Lewis lung carcinoma and found to be significant and comparable to their chloroethyl counterparts.On the basis of results from both systems, the dihydroxycyclohexyl derivative 6b may be the most effective.
- Johnston, Thomas P.,Kussner, Conrad L.,Carter, Ronald L.,Frye, Jerry L.,Lomax, Nancita R.,et al.
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p. 1422 - 1426
(2007/10/02)
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