Nitrobenzene, reactions with methane

The chemical ionization MS of a selection of substitued nitrobenzenes have been studied106. The H2 chemical ionization MS appeared significantly more useful for characterization of, e.g., isomeric compounds than the corresponding methane spectra, apparently due to the higher internal energy deposited in the protonated molecule by the reaction with H3+, and consequently in the more extensive fragmentation106. 

Titanium dioxide suspended in an aqueous solution and irradiated with UV light X = 365 nm) converted benzene to carbon dioxide at a significant rate (Matthews, 1986). Irradiation of benzene in an aqueous solution yields mucondialdehyde. Photolysis of benzene vapor at 1849-2000 A yields ethylene, hydrogen, methane, ethane, toluene, and a polymer resembling cuprene. Other photolysis products reported under different conditions include fulvene, acetylene, substituted trienes (Howard, 1990), phenol, 2-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol, 2,6-dinitro-phenol, nitrobenzene, formic acid, and peroxyacetyl nitrate (Calvert and Pitts, 1966). Under atmospheric conditions, the gas-phase reaction with OH radicals and nitrogen oxides resulted in the formation of phenol and nitrobenzene (Atkinson, 1990). Schwarz and Wasik (1976) reported a fluorescence quantum yield of 5.3 x 10" for benzene in water. 

Ring fluorination is observed in reactions of protected aniline derivatives, with the ojp ratio of the products, e.g. 11-13, being dependent on the substituent 5 nitrobenzene is unreactive towards electrophilic substitution. The polymerization process may be studied by di-fluorobis(fluoroxy)methane reactions with variousfluoro-substituted benzene derivatives (hexa-... 

Kinetic studies on the nitration of nitrobenzene by nitronium borofhioride in the polar solvents sulphuric acid, methane-sulphuric acid, and acetonitrile show the reaction to be first-order in both nitronium salt and aromatic110. With the first two solvents, the rate coefficients are similar for nitration by nitric acid and by the nitronium salts, indicating a common nitrating entity. With acetonitrile the rate coefficients are very much lower, consistent with a much lower concentration of free nitronium ions in this medium and thus with the nitronium salts existing as ion pairs in organic solvents (see Table 25). 

Simultaneous reaction of dimedone, formaldehyde, and aromatic amines in nitrobenzene and in the presence of perchloric acid gave 10-aryldecahydroacridines 356 (R = H) together with the perchlorate salts 357 (82ZOR1460). The same products 356 and 357 (R1 = Ph) were obtained in much higher yield from reaction of bzs(dimedonyl)methane... 

Glacial acetic acid is a suitable solvent for use with silver acetate and CC14 or, up to 150°, nitrobenzene for use with silver trifluoroacetate. The Hunsdiecker reaction (see p. 1005) may intervene as competing reaction 377 trifluoroiodo-methane, for example, may be formed when iodine, silver trifluoroacetate, and nitrobenzene are heated in the absence of a substance that can be iodinated CF3COOAg + I2 ------------------------ CF3I + Agl + C02... 

With the advent of esr spectroscopy aromatic-antimony pentachloride precipitates were shown to contain the aromatic cation radical (Weissman et al., 1957), and this in turn accounted for the earlier discovery of paramagnetism in the salts obtained from reaction of aromatic amines with antimony pentachloride (Kainer and Hausser, 1933). Characterization of cation radicals in nitro-methane and nitrobenzene solutions of antimony pentachloride by visible spectroscopy soon followed. Eventually, by working with degassed solutions of antimony pentachloride in dichloromethane at —70° it was possible to obtain esr spectra of aromatic hydrocarbon cation radicals with extraordinarily well-resolved hyperfine patterns (Lewis and Singer, 1965, 1966). Similar success was obtained with alkyl aryl ether (Forbes and Sullivan, 1966), and organosulfur cation radicals in aluminum chloride-nitromethane solutions at —50° (Shine and Sullivan, 1968 Sullivan, 1968). In this work, resolution... 

MDI Chemistry. Methylene diphenylene isocyanates are a product of the reaction of aniline, formaldehyde and phosgene. The first step is the reaction of aniline (made by hydrogenation of nitrobenzene) with formaldehyde to form the intermediate bis(aminophenyl)methane. The chemistry is shown in Eq. (2). The bis(aminophenyl)methane is then reacted with phosgene to yield dimeric and trimeric isocyanates as shown in Eq. (3) [4]. 

The stabilization of the radical cation in SDS micelles is consistent with the formation of the surface complex already mentioned in Sect. 2.1.1. There are a number of examples of the stabilization of radical ions in micelles of the opposite sign. The electrochemical reduction of nitrobenzene in homogeneous solutions is two-electronic, but in micellar CTAB solutions it is resolved into two separate reactions [135]. So the presence of cationic micelles inhibits the disproportionation of nitrobenzene radical anions. It may be caused by the reduced mobility of the radical ions in the surface layer of the micelles due to complex formation with the end groups of the micelles. It can account for the inhibition of the disproportionation because the latter needs a coUision of two radical ions. The salt formation of the radical cation of N-methylphenothiazine with the end groups of SDS micelles was proposed in the study of electrochemical oxidation of N-methylphenothiazine in micellar solution [136]. Tetracyanoquinodi-methane is solubilized in dodecylpyridinium-inverted micelles in the form of a radical anion with the oxidation of the iodide ion [137]. 

Mti oai omatics are relatively inert to foimaldehj de. Ho ve ei, when nitrobenzene, o- and p-nitrotoluene, respectively, are heated xvith foiTualde-hyde in the presence of concentrated sulfuric acid at -y>-50°C for 24-36 hours, dinitrodiphenylmethane and two isomeric dmitrotoluenes are obtained . According to Parkes and Morley-, s.vni. 3,3-dinitrodiphenyl-methane is produced from nitrobenzene and formaldehyde by this reaction. Chloromethjdations of aromatic nitro compounds may also be brought about with formaldehy de and hydrogen chloride, as exemplified by an I. G. 

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