Benzaldehydes, nitroso

Sodium dodecyl sulfate and hydrogen dodecyl sulfate have been used as catalysts in the denitrosation iV-nitroso-iV-methyl-p-toluenesulfonamide [138]. The kinetics of condensation of benzidine and p-anisidine with p-dimethylamino-benzaldehyde was studied by spectrophotometry in the presence of micelles of sodium dodecyl sulfate, with the result that the surfactant increases the rate of reaction [188]. The kinetics of reversible complexation of Ni(II) and Fe(III) with oxalatopentaaminecobalt(III) has been investigated in aqueous micellar medium of sodium dodecyl sulfate. The reaction occurs exclusively on the micellar surface [189]. Vitamin E reacts rapidly with the peroxidized linoleic acid present in linoleic acid in micellar sodium dodecyl sulfate solutions, whereas no significant reaction occurs in ethanol solution [190]. 

Photochemistry of (2-nitrophenyl)diazomethane 70 has been studied by excitation at 350 nm in argon matrix isolation system54. That shows that at 10 K, 2-nitroso-benzaldehyde is formed by intramolecular oxygen migration from (2-nitrophenyl) carbene... 

The methyl group of TNT will condense with aldehydes in a similar way to other substrates containing acidic protons. TNT (1) reacts exothermically with benzaldehyde in alkaline solution to form 2,4,6-trinitrostilbene (140). 2,4,6-Trinitrobenzaldehyde (142) is synthesized from the base hydrolysis of the imine (141) formed from the condensation of TNT (1) with /t-nitroso-N,N-dimethylaniline. ... 

Durch Kondensation von 2-Phenyl-2-oxo-acethydroximsaure-chlorid und Benzamidin-Hydro-chlorid erhalt man 2,4(5)-Diphenyl-5(4)-nitroso-imidazol (s.Bd. X/l, S. 1071). 2,2-Dicyan-3-phenyl-oxiran reagiert mil Amidinen unter Abspaltung von Benzaldehyd zu 4-Amino-5-cyan-imidazol115. Ein Beispiel fur diese Reaktion ist die U msetzung mit N-Phenyl -benzamidin zu 4-Amino-5-cyan-1,2-diphenyl-imidazol (80%) ... 

Scheme 17.6 Production and reaction of unwanted nitroso-benzaldehydes associated with the use of nitrobenzyl linkers.

Because quinine does not meet the generally accepted requirements of a chemical actinometer (Bunce, 1989), possible alternatives have been investigated. Recent work (Allen et al 2000) has confirmed that 2-nitro benzaldehyde (2NB) is converted to 2-nitroso benzoic acid on irradiation, following the original work (Pitts, 1966), and that the amount of acid formed can be readily estimated by titration. Alternatively, the amount of base corresponding to the acid liberated after the required exposure can be calculated and added to the 2NB solution before exposure. By monitoring the pH or adding phenolphthalein as an indicator, the end-point can readily be determined. 

Durch die Einwirkung von Licht lassen sieli 2-Nitro-benzaldehyd-acetale in 2-Nitroso-bmzoesiiureeder umwandeln1-3 z. B. ... 

The net outcome of the Sommelet reaction is the oxidation of the benzyl methylene position into the corresponding carbonyl, and in that sense, the Krbhnke reaction may be considered a close variant. The KrOhnke reaction transforms benzyl halides to benzaldehydes using pyridine and an aromatic nitroso compound 16.16,17 As shown below, quaternary pyridinium salt (15) is formed from addition of pyridine to benzyl halide 1. Oxidation of 15 with p-nitrosodimethylaniline (16) affords nitrone 17, which is then hydrolyzed to benzaldehyde 3 and hydroxylamine 18. 

Methyl Alcohol Methyl Alcohol Ethyl Alcohol Ethyl Alcohol Glycol Glycol Acetonitril Acetonitril Propionitril Propionitril Benzonitril Methyl Sulphocyanide Ethyl Sulphocyanide Nitro Methane Nitro Methane Nitroso Dimethylin Acetyl Acetone Furfurol Furfurol Benzaldehyde Salicylaldehyde... 

If highly reactive dipolarophiles, such as benzaldehyde and nitroso-benzene, are used, equilibrium is not established and two different pair of diastereoisomers are formed... 

Oxidation. Most oxidising agents react with tropylium ions to give benzene derivatives, especially benzaldehyde. Reagents used include chromic oxide [16], permanganate [61,62], silver oxide [16], metal ions [SS,63] and also mild reagents such as nitrobenzene, nitroso--compounds or sodium nitrite [63]. The type of mechanism proposed is as follows ... 

As an example, the photodegradation products of chloramphenicol (nitroso-compounds and paranitro-benzaldehyde) are considered carcinogenic. These products will be formed in vitro and in vivo and can reach the bone marrow in rats [37]. Chronic use of chloramphenicol has been coimected with bone marrow depression, not caused by chloramphenicol itself. Apart from the question if this risk is estimated well [38], it can be avoided completely if the patient covers his skin if a dermal preparation has been applied and only use chloramphenicol as eye ointment 1 % at night. See also Sect. 10.5. 

The N-nitroso and nitrodiphenylamines (Fig. 188 and Chapter P) were separated by chromatographing with acetone-benzene-petrol ether (1 -f 49.5 + 49.5) in the first direction and ethyl acetate-petrol ether (20 + 80) in the second. Visualisation was likewise with 4-diethylamino-benzaldehyde reagent (similar to No. 72). 

Dibrom4-iiitro.benzaldehyd 7 O 204. 3.S.I>ibTom.2-nitroso-benzaeBiure 9 O 242. 

C Hi NaOs Nitroso anWdro-tri8-[2-ammo benzaldehyd] 14 I116. 

Michalak J, Gebicld J, Bally T (1993) Radiation induced transformations of benzaldehydes carrying formyl, nitro or nitroso substitucaits in ortho position. J Chem Soc Perkin... 

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