Baudisch reaction

An interesting reaction, the Baudisch reaction, involves the formation of nitrosophenols by the action of hydroxylamine hydrochloride and hydrogen peroxide, in the presence of metallic ions or certain Werner complexes, on aromatic compounds. The products are primarily o-nitrosophenol complexes of the metallic ion. Unfortunately, this reaction requires further development before it can be considered a reliable preparative procedure. 

The Baudisch reaction permits conversion of aromatic hydrocarbons to nitrosophenols. 

Baudisch reaction. Synthesis of o-mtrosophc-nols from benzene or substituted benzenes, hydrox-ylamine, and hydrogen peroxide in the presence of copper salts. 

Sodium pentacyuno-a in wine-ferrate o-Nitrosophenols from hydrocarbons Baudisch reaction s. 3, 298 Nas[Fe(CN)zNHa ... 

The Baudisch reaction295 makes it possible simultaneously to introduce a nitroso and a hydroxyl group in the ortho-position to one another. In this reaction NOH radicals are produced by oxidation of hydroxylamine or reduction of nitrous acid these radicals, in conjunction with an oxidizing agent and in the presence of a copper salt as catalyst attack the aromatic nucleus. Yields are seldom very high, but few o-nitrosophenols are easily prepared in other ways. Cronheim296 has reported the first preparation of fifty mono-and di-substituted n-nitrosophenols by the Baudisch reaction. 

Other references related to the Baudisch reaction are cited in the literature. 

Barton-Kellogg Reaction Barton-McCombie Reaction Barton-Zard Reaction Baudisch Reaction Bauer (see Haller-Bauer Reaction)... 

An intriguing method for preparing phenolic nitroso compounds was discovered by Baudisch [95]. Interestingly enough, the product mixture from the reaction appears to be primarily the ortho-substituted phenol, a class of compounds of which very few examples seem to have been described. 

Baudisch, O. and Hartung, W.H., Inorg. Syriih.. Vol. 1, 185, cited after Nauer, G. et al.. Spectroscopic and thermoanalytical characterization of standard substances for the identification of reaction products on iron electrodes, 7. Therm. Anal., 30, 813, 1985. 

There is not sufficient data available as yet to say what reactions are involved in the rapid catalytic decomposition by the aquo salts, and clearly a separate study in the absence of ferro- and ferri cyanides is required. However Baudisch (89) and Petow and Kosterlitz (90) have shown that like ferrous and ferric ions they can behave peroxidatically with suitable organic substrates. Also Baxendale et al. (45) have found... 

Baudisch and Cronheim postulated that some of the cupric ion which is reduced to cuprous ion, which forms the complex [Cu(NO)] with nitrosyl radicals that were generated via the prior oxidation-reduction reactions among the various reagents. Then this complex attacks the aromatic ring, leading to nitrosation, followed by the hydroxylation adjacent to the position of nitrosation. However, this mechanism has been questioned. A tentative mechanism is thus proposed here. 

Scheme 14.6. A representation of the formation of uracil bythe reaction between malic acid and urea in the presence of sulfuric acid (after Davidson, D. Baudisch, O. /. Am. Chem. Soc., 1926, 48, 2379).

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