Nitration, of arenes

In the nitration of arenes with N2C>4, the red-coloured transient arises from the metastable precursor complex [ArH, NO+]NC>3 which is formed in the prior... 

Nitration of arenes. Reaction of 1-naphthol with CAN in acetic acid results in 2,4- and 4,6-dinitro derivatives. The reaction with CAN absorbed on silica gel results in 2-nitro- and 4-nitro-l-naphthol in 42 and 38% yield, respectively. Polynuclear arenes are not oxidized to quinones by CAN supported on silica but are converted mainly into mononitro derivatives. Thus phenanthrene is converted into 2-nitrophenanthrene (45% yield) and 3-nitrophenanthrene (28% yield).1... 

Suzuki, H. and Mori, T. Unusual isomer distribution of dinitrobenzenes and nitrophenols formed as side products during the ozone-mediated nitration of benzene with nitrogen dioxide - further evidence for the alternative mechanism of electrophilic nitration of arenes. J. Chem. Soc., Perkin Trans. 2, 1995, 41 44. 

Catechols and hydroquinones can be converted (91-98%) into quinones by cerium(IV) salts coated onto silica as free-flowing yellow powder from impregnation with cerium(IV) ammonium nitrate. This reaction is usually performed in the presence of magnesium sulfate. The same (NH4)2Ce(N03)6 SiQ2 reagent in the dry state effects oxidative nitrations of arenes. For example a-mq>hthol is converted to the Orth) (42%) and the para (38%) nitro compounds, while its metiiyl or ethyl ethers give exclusively the para nitration product (equation 4). In solution, the products are cmtaminated with the products of dinitration and of oxidation into quinones. ... 

Nitration of arenes. Using YbfOTfjj it is possible to nitrate arenes with 69%... 

Ytterbium(III) Triflate as a Recyclable Catalyst for the Nitration of Arenes with Nitric Acid... 

Nitration of arenes (Section 12.3) The standard method for introducing a nitrogen atom as a substituent on an aromatic ring is nitration with a mixture of nitric acid and sulfuric acid. The reaction proceeds by electrophilic aromatic substitution. 

Nitration of arenes. The active reagent may be nitryl chloride (NO2CI). It can nitrate PhCOOMe and PhCF, in good yields at room temperature. 

Nitration of arenes. The mixture of MejSiCl, NaNOj, and AlClj form an effective nitrating agent in CCU, which is probably N02 A1C14 (8 examples, 62-97% yield). 

The mechanism described above is analogous to that proposed for the nitration of arenes by tetranitromethane [51]. It is known that an arene and... 

Halogenation and nitration of arenes, substitution reactions ofaliphatics Ether and ester formation, thiols from alcohols and H2S, amines from alcohols and NHj (mordenite, erionite)... 

Sc(OTf)3 shows high catalytic activity for the nitration of arenes with nitric acid. Sequential Claisen rearrangement/cyclization of allyl phenyl ethers is efficiently catalyzed by Sc(OTf)3 at high temperature in an ionic liquid to give 2,3-dihydrobenzofurans. ... 

Zaraisky. A.P. Kachurin. O.I. Velichko, L.I. Shur. V.B. Tikhonova. LA. Furin. G.G. Phase transfer catalysis in reactions of electrophilic substitution. VIII. Phase transfer catalytic nitration of arenes with sodium nitrite in an acidic medium. Zh. Org. Khim. 1999, 35. 1063-1067. 

Nitration of arenes still attracts much attention, and of particular interest are selective nitrations of polycyclic aromatic... 

Nitration of arenes followed by reduction of the nitro group to a primary amine (Section 22.IB)... 

Amines can be prepared using reactions including epoxide ring opening, addition of nitrogen nucleophiles to carbonyls followed by reduction, reduction of amides, reduction of nitriles, and nitration of arenes followed by reduction. 

Problem 6.15. Using the information present in Scheme 6.83, account for the observation that water (H2O) is deleterious to the progress of nitration of arenes with nitric (HONO2) and sulfuric [(H0)2S02] acids. 

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