- Ethylammonium nitrate (EAN)/Tf2O and EAN/TFAA: Ionic liquid based systems for aromatic nitration
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Acting as in situ sources of triflyl nitrate (TfONO2) and trifluoroacetyl nitrate (CF3COONO2), the EAN/Tf 2O and EAN/TFAA systems, generated via metathesis in the readily available ethylammonium nitrate (EAN) ionic liquid as solvent, are powerful electrophilic nitrating reagents for a wide variety of aromatic and heteroaromatic compounds. Comparative nitration experiments indicate that EAN/Tf2O is superior to EAN/TFAA for nitration of strongly deactivated systems. Both systems exhibit low substrate selectivity (K T/KB = 5-10) in (Figure presented) between values reported for covalent nitrates and preformed nitronium salts.
- Aridoss, Gopalakrishnan,Laali, Kenneth K.
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experimental part
p. 8088 - 8094
(2011/11/13)
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- Formation of 4-Halo-4-nitrocyclohexa-2,5-dienones on Nitration of p-Halophenols and p-Halophenyl Acetates.
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Nitration of p-chloro-, p-fluoro-, and p-bromo-phenol or the corresponding p-halophenyl acetates at -40 deg C and below gives the 4-halo-4-nitrocyclohexa-2,5-dienones in addition to the 4-halo-2-nitrophenols.The dienones isomerize to the nitrophenols at temperatures between -40 deg C and 0 deg C.Nitration of 4-chloro-2-methylphenol or its acetate gives both 4-chloro-2-methyl-4-nitrocyclohexa-2,5-dienone and 4-chloro-6-methyl-6-nitrocyclohexa-2,4-dienone. 4-Chloro-3-methylphenol and its acetate give 4-chloro-3-methyl-4-nitrocyclohexa-2,5-dienone.
- Clewley, Robin G.,Cross, Gordon G.,Fischer, Alfred,Henderson, George N.
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p. 1299 - 1310
(2007/10/02)
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