1905.| The Synthesis of a Substance allied to Adrenalin. 493 
characteristic of adrenalin. It is true, further, that since the synthetic pro- 
duct would necessarily be optically inactive, one would expect slight differences 
between the artificial and natural bases, but on the other hand there are 
certain chemical differences, which will be mentioned later, which I am 
inclined to think are greater than would be the case if the two substances 
were stereo-isomeric. This involves the conclusion that either adrenalin or 
the synthetical base has not the structure represented by the formula 
CsH3(OH)2,.CH(OH).CH2N HCHs3. 
A substance which I believe to be identical with the base that I have 
prepared has been obtained by Meister Lucius and Briining’s chemists by the 
action of aluminium shavings and mercuric sulphate upon methylamino- 
acetylecatechol. They definitely ascribe the above formula to the substance, 
and this, if correct, would necessitate an alteration in the provisional struc- 
tural formula of natural adrenalin. But it must be remembered that the 
synthetical base has been obtained by a reaction which is well known to give 
more than one product. Ketones commonly give a mixture of the corre- 
sponding secondary alcohol and pinacone upon reduction, either of which 
substances may constitute the main product. In the reaction under considera- 
tion the pinacone would have the following structure :— 
Moreover, it must be remembered that the reaction is carried out, as will 
be seen later, under conditions which may quite well induce further changes 
in such unstable substances. Owing to experimental difficulties it is 
impossible at present to settle the point definitely, but I am of opinion that 
with the evidence at present available one is not justified in selecting 
preferentially any one of the several possible formal for the synthetical base. 
The synthetical substance is extraordinarily active as regards the blood- 
pressure and certain other physiological effects. 
Mr. T. R. Elliott was kind enough to examine some of the substance and 
informs me that so far as the experiments went they revealed no difference 
- between the stimulating action—both motor and inhibitor—of the laboratory 
and of the animal products. Such close physiological resemblance may be 
taken as some evidence in favour of a close structural relationship between 
the two substances. 
