PROCEEDINGS 
OF THE 
NATIONAL ACADEMY OF SCIENCES 
Volume 8 APRIL 15. 1922 Number 4 
THE OXIDATION OF HYDROQUINOL IN THE PRESENCE OF 
ALIPHATIC AMINES 
By R01.1.A N. Harger^ 
Department of Chemistry, Yale University 
Communicated by Treat B, Johnson, March, 1922 
That hydroquinol is converted by oxidation in neutral and acid solutions 
into quinone, with the intermediate formation of quinhydrone, was first 
demonstrated by Wohler in 1844.^ This reaction appears to proceed 
quantitatively and the change can be brought about by the use of a great 
variety of oxidizing agents. 
When we turn, however, to the oxidation of hydroquinol in alkaline 
solution the situation is far more complicated and at present we must 
admit that we have not an accurate understanding of the various changes 
which take place. The writer's interest in this phase of the subject re- 
sulted from the observation that an aqueous solution of hydroquinol, 
made strongly alkaline with methylamine, rapidly absorbs oxygen gas at 
ordinary temperatures with formation of a brilliant purple colored com- 
pound which is characterized by its pronounced crystalline habit. 
It is of course well known that alkaline solutions of hydroquinol absorb 
oxygen, but if one will substitute an aliphatic amine, like methylamine, 
for the alkali usually employed he will observe an absorption of oxygen 
which is unusual both for its rapidity and in regard to the quantity con- 
sumed. The characteristic reactions which take place under these con- 
ditions appear to have not been studied. 
For example, if hydroquinol is dissolved in a strong aqueous solution of 
mono- or dimethylamine and this solution is placed in a tube and exposed 
to oxygen, the liquid rapidly assumes a brownish red color and within an 
hour the deposition of a considerable quantity of beautiful red plates is 
observed. At the end of twenty-four hours the solution is almost filled 
with these brilliant crystals and for each gram of hydroquinol used there is 
absorbed about 250 cc. of oxygen. If the oxidation is continued for two 
or three days more the total absorption will increase to 500-600 cc. of oxy- 
gen per gram of hydroquinol, or from 10 to 12 equivalents of oxygen for 
