Forster reaction diazo compounds

N-Nitrosation of oximes by nitrosyl halides or nitrite esters often results in the formation of N-nitrimines, R R C=NN02, these compounds being formed by rearrangement of the initial adducts. N-Amination of oximes by chloramine or by hydroxylamine-O-sulfonic acid can result in the formation of diazo compounds (Scheme 28). The reaction, known as the Forster reaction, has been used for the preparation of aryldiazoalkanes, although better methods are usually available. Diazo ketones of the general formula (49) have also been prepared by this method from the oximes. "... 

The most frequent synthetic approaches, summarized in Scheme 4, are towards the primary photophores. The preparation of aryl azide derivatives follows the typical retro-synthetic pathway in the majority of the reported cases (Scheme 4 A), and, practically, diazotation is the most commonly used procedure [24 - 29]. In the case of diazirines only one major synthetic sequence is repeated ammonolysis of oximes followed by dehydrogenation (Scheme 4B) [30-32]. There are various ways of preparing diazo- or diazocarbonyl-compounds most frequently the Forster and Bamford-Stevens reactions (Scheme 4C) are employed [33-37]. 

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