Miss Thomas and Mr Jones, Active Nitrogen Compounds. 33 



Some Optically Active Nitrogen Compounds. By Miss M. B. 

 Thomas and H. 0. Jones, M.A., Clare College. 



[Bead 14 November 1904.] 



The work was undertaken in order to institute a quantitative 

 comparison of the molecular rotatory powers of different substi- 

 tuted quaternary ammonium bases. The compounds of this type 

 which have hitherto been described give salts with camphor- 

 sulphonic and brom-camphor-sulphonic acids which are stable and 

 easily soluble in water. These salts can, in many cases, be resolved 

 into their d and I components by fractional crystallisation from 

 suitable solvents. Since the molecular rotation of salts of active 

 acids and bases in dilute aqueous solution is the sum of those of 

 the acidic and basic ions, the rotation of the basic ion can be 

 obtained by subtraction of that of the acidic ion from the total 

 molecular rotation. Since the rotatory power of an ion appears to 

 be unaffected by many of the conditions which alter that of liquids 

 or of non-electrolytes in solution to a considerable extent, it is 

 possible that any regularities which exist may be more evident 

 in the values for ions. The bases investigated are those in which 

 three of the groups substituting ammonium hydrogen atoms 

 (phenyl, benzyl, and methyl) are kept the same, while the fourth 

 is successively replaced by the isopropyl and isoamyl radicals. 

 The brom-camphor-sulphonates or camphor-sulphonates of these 

 bases respectively were prepared by Pope and Peachey's method, 

 and fractionally crystallised until a constant rotation was obtained. 



Phenyl-benzyl-isopropyl-methyl ammonium iodide was obtained 

 by mixing methyl-isopropyl-aniline with benzyl iodide in mole- 

 cular proportions. The iodide thus formed was recrystallised from 

 methylated spirit (m.p. = 133° C.) and heated with the calculated 

 quantity of silver d brom-camphor-sulphonate in ethyl acetate. 

 The solution after filtration from the precipitated silver iodide de- 

 posited crystals of phenyl-benzyl-isopropyl-methyl ammonium d 

 brom-camphor-sulphonate (m.p. = 184° C). This was recrystallised 

 from (1) ethyl acetate or (2) water. The salt of the laevo base is 

 the less soluble in both liquids, and after three crystallisations 

 from either, a constant molecular rotation ([M] D = — 123°) in dilute 

 aqueous solution was obtained. Thus for the laevo basic ion 

 [M] D = — 393° ([M] D for d brom-camphor-sulphonic ion = 270°). 



I phenyl-benzyl-isopropyl-methyl ammonium iodide was precipi- 

 tated from the brom-camphor-sulphonate by addition of potassium 

 iodide to the water solution. The active iodide melts at a slightly 



VOL. XIII. PT. I. 3 



