376 
Mr Jones, Resolution of Optically active 
Resolution of Optically active Ammonium Salts by means of 
Tartaric Acid. By H. O. Jones, M.A., Clare College. 
[ Read 25 November 1907.] 
The first pure optically active ammonium compound was 
isolated by Pope and Peachey {Trans. Cliem. Soc. 1899, lxxv. 
1127), who then expressed the opinion that previous failures to 
resolve these compounds by means of tartaric and camphoric 
acids were due to hydrolysis : they therefore used strong acids and 
hydroxyl free solvents. That hydroxyl free solvents are un- 
necessary was shown (Thomas and Jones, Trans. Chem. Soc., 190G, 
lxxxix. 280) when it was found that two brom-camphor-sul- 
phonates were resolved on crystallising from water ; and that a 
strong acid is not essential was shown by Miss Homer {Proc. 
Camb. Phil. Soc. 1907, xiv. 196) by resolving one of these 
asj^mmetric nitrogen compounds by means of tartaric acid. 
Recently tartaric acid has been found extremely useful in 
resolving certain asymmetric nitrogen compounds which were not 
resolved or only resolved with great difficulty by the use of 
camphor-sulphonic and brom-camphor-sulphonic acids. The acid 
tartrates were found to be resolved on crystallising from alcohol. 
This paper contains a preliminary account of the results in 
one particularly interesting case. 
The second optically active nitrogen compounds to be prepared 
were the phenyl-methyl-ethyl-benzyl ammonium salts resolved by 
the writer {Trans. Chem. Soc. 1903, lxxxiii. 1419; 1904, lxxxv. 
223) by fractional crystallisation of the dextro- and laevo-camphor- 
sulphonates from a warm mixture of ethylal and ethyl acetate. In 
this way the d-base d-acid salt was obtained having [M] D = + 71° 
in aqueous solution, and the Z-base Z- acid salt with [M] D = — 71 - 2°. 
The molecular rotatory powers of the basic ions are there- 
fore -f 19’3° and — 19‘6° respectively. The active iodides gave 
[M] d = + 30° in alcohol. 
A similar result was obtained by Wedekind {Ber. 1904, xxxvn. 
2727) using methyl formate as solvent. 
Later, when examining a whole series of active ammonium 
salts to determine the effect of constitution on their rotatory 
powers, this salt was reexamined (Thomas and Jones, loc. cit. 286) 
with practically the same result. 
It then became evident that this salt was quite out of place 
in the series since the value of [M] D for the corresponding w-propyl 
ion was 299° and for the isopropyl ion 398°. 
It seemed extremely probable that the method used had not 
effected complete resolution, although the rotatory power of the 
salt was constant on recrystallisation. Attempts were therefore 
