Synthesis of diazo reagents

Because the Wolff rearrangement limits their utility diazoacetyl reagents and diazoketones are now seldom used (but see, Ganjian et al., 1978 Sen et al., 1982). Useful guides to the literature on their syntheses have been given by Bayley and Knowles (1977) and by Sen (1982). 

Thep-nitrophenyl ester of diazomalonic acid has been made. While this derivative proved useful for acylating the serine residues at the active sites of trypsin and chymotrypsin (e.g. Vaughan and Westheimer, 1969a,b  

Hexter and Westheimer, 1971b) it is not a particularly active ester and the A -hydroxysuccinimide ester, made from the acid choride, is better used for the acylation of amino groups (Bispink and Matthaei, 1973, 1977). 

Recently, Stackhouse and Westheimer (1981) described the properties of (dansyldiazomethyl)methylphosphinic acid derivatives. They prepared O- and. S -esters, and a phosphoramide by reactions of the acid chloride, formed in situ, in the presence of the catalyst dimethylaminopyridine (Fig. 3.21). 

Using [3H]dansyl chloride as the starting material, [3H]dansyldiazome-thane was synthesized in three steps at a specific radioactivity of up to 

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