Diazo-fatty acid esters

Most certainly, Curtius did not intend to enter protein chemistry when he started his work on hippuric acid and glycine. In the following years he was mainly fascinated by his discovery of diazo-fatty acid esters and the multitude of their reactions and so scarcely acquired interest in peptones and albuminoids. During the last decade of the past century, however, stimulated by E. Fischer s vigorous activity, Curtius resumed his studies, by which he contributed so much to modern peptide chemistry. It is somewhat ironical that Fischer s engagement, that had an immense echo at that time left less practical application for peptide chemistry than Curtius invention of the azide coupling method. Emil Fischer s great merit is to have drawn the attention of the whole scientific world to the field of proteins, whose mystery could be revealed by application of chemical methods and to lend trust to chemists that they are able to synthesize complicated natural substances like peptides. 

Dizad 6. [Blackman Uhler] Polyoxyethylene ester of fatty acids nonfoaming stabilizer for diazo bath in naphthol dyeing and printing. 

Alkylation describes the reaction where an active hydrogen is replaced with an alkyl group, for example, a methyl group. Most polar groups can be alkylated, and many reagents can be used, for example, alkyl halogenides, diazo alkanes, and N,N -dimethylformamide dialkyl acetal. An example of an alkylation is the formation of methyl esters of fatty acids by using methanolic BF3, where boron trifluoride (BF3) acts as a catalyst. 

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