Dr Fenton, Note on the detection of Malonic Acid. 477 
Note on the detection of Malonic Acid. By Dr H. J. H. 
Fenton, Christ’s College. 
[Read 18 May 1914.] 
An account was given, in a previous communication to the 
Society, of a reaction of malonic ester with bromomethylfurfural 
which serves for the identification of hexoses. When these two 
compounds are mixed together in alcoholic solution and the 
mixture is made just alkaline with alcoholic potash, an intense blue 
fluorescence results, which is persistent at very great dilution. 
Conversely, this reaction may be employed as a distinguishing 
test for free malonic acid, or its salts. The substance is mixed 
with anhydrous methyl or ethyl alcohol containing hydrogen 
chloride, or sulphuric acid warmed and allowed to stand for a few 
minutes; the mixture is then neutralised and tested with bromo- 
methylfurfural in the manner described. The production of this 
blue fluorescent substance, under the conditions specified, appears 
to be entirely characteristic of malonic ester and ethyl malonic 
ester. Other esters containing labile hydrogen atoms, such as 
acetoacetic and dicarboxyglutaconic esters, do not behave similarly. 
