Acid catalyzed hydrolysis of aliphatic diazo compounds

Acid catalyzed hydrolysis of aliphatic diazo compounds 

The kinetics of acid catalyzed hydrolysis of ethyl diazoacetate in aqueous solution was studied for the first time by Bredig and Fraenkel [195] in 1905, and the decomposition kinetics of diphenyldiazomethane in aprotic solvents was investigated by Staudinger and Gaule [196] in 1916. Reinvestigations of the ethyl diazoacetate hydrolysis were carried out by Bronsted et al. [197] and Moelwyn-Hughes and Johnson [198], The reaction was followed by gas volumetric measurement of the evolved nitrogen. Ultraviolet spectrophotometric [199] and thermometric [200] methods were applied in more recent studies which were concerned with a variety of different diazo compounds. A review article [201] was published in 1967 even more new material is available today. 

The products of hydrolysis of an aliphatic diazo compound are nitrogen and the corresponding hydroxy compound, viz. 

The reaction is catalyzed by acids but not by bases. In the presence of nucleophiles, such as halide ions, substituted compounds are formed as side products, viz. 

According to the findings of kinetic and mechanistic studies of the hydrolysis reaction, the aliphatic diazo compounds may be divided into the following three groups (a) ethyl diazoacetate, primary diazoketones, primary diazosulfones, 2,2,2-trifluorodiazoethane (b) diaryldiazo-methanes, 9-diazofluorene and ring substituted derivatives, p-nitrophenyl- 

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The only known example of this mechanism is the acid catalyzed hydrolysis of aliphatic diazo compounds (see Sect. 8). 

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