COCAINE. 
36l 
§ 429 -] 
Tropacocaine (benzoyl-</f-tropin), 
Ci 5 Hi 9 N0 2 = CH 2 —CH-CH 2 
N.CH 3 CH.O(C 6 H 5 CO) 
CH 2 —CH—CH 2 . 
The base is crystalline, in the form of tabular crystals, having 
the low melting-point of 49°, alkaline in reaction. Water scarcely 
dissolves tropacocaine, but it is easily soluble in most organic 
solvents. 
The hydrochloride is in therapeutic use as a local anaesthetic; 
it has been used largely to produce spinal analgesia. It is less 
toxic than cocaine, and has but slight action on the pupil. The 
picrate forms needles, m.p. 240°-242°. The chemical tests are 
similar to those for cocaine. 2 per cent, solution of potassium 
bichromate gives thin yellow, doubly refracting crystals ; extinc¬ 
tion angle 24°. The sharp angles at the summit of the crystals 
measure 32°. 
Euphthalmin, c 17 h 25 no 3 , is N-methy 1- a-methyl-a '-dimethyl-y-phenyl- 
glykolyl-oxypiperidine. 
Acoin, C 23 H 25 N 3 0 3 , is the hydrochloride of di-p-anisyl-monophenetyl- 
guanidine. The crystals melt at 176° ; they are insoluble in ether, but 
easily soluble in alcohol or in water. Acoin has a bitter taste and 
numbs the tongue. 
Holocaine, C 18 H 22 N 2 0 2 .HC1, is in the form of white crystals. The 
crystals dissolve in 45 parts of cold water, but easily in hot water. The 
crystals have a bitter taste and numb the tongue ; the effects are but 
transient. Both holocaine and acoin give the indo-phenol reaction—a 
blue colour produced by first treating a solution with hypochlorite and 
then adding phenol and ammonia, and precipitate with potassium 
bichromate. 
Novocaine, C 13 H 20 N 2 O 2 .HCl, is the hydrochloride of p-amino-benzoyl- 
diethyl-amino-ethanol = 
y NH 2 (1) 
C 6 h/ (CH 2 ) 2 .N(C 2 H 5 ) 2 HC1 . 
X C0 2 (4) 
The base is a colourless oil, which on standing becomes crystalline. 
The hydrochloride melts at 156°. The physiological test gives similar 
results to cocaine. The picrate melts at 153°-154°. Dinitrobenzoic 
acid gives a precipitate of doubly refracting dichroic orange-yellow 
prisms. 
