Antiseptic Action and Chemical Constitution. 



343 



compared with 2.7.diamino-6.methylphenazine [85], suggests that methyl 

 groups attached directly to the benzene rings may play a part in enhancing 

 the antiseptic power in this series. For Staphylococcus aureus in serum 

 the methochlorides of 2.dimethyl amino-7.amino-6.methylphenazine [84], 

 2.7.diamino-3.6.dimethylphenazine [86], and 2.aminonaphtho-7.amino- 

 6.methylphenazine [87] are powerful antiseptics, practically equal to the 

 most potent of the acridine series ; on the other hand, they are markedly 

 inferior to the latter in their action on B. coli. 



It cannot be said that the behaviour of the phenazine series throws any 

 clear light on the antiseptic properties of the diaminoacridine group. 



Amino Pyridine Derivatives [1.2.]. — ex.- Amino pyridine was obtained by the 

 method of Tschtschibabin and Leide.* It melted at 57-58° as stated by the 

 authors of the process. By heating with a slight excess of acetic anhydride 

 and some fused sodium acetate it was converted into the acetyl derivative 

 which solidified on pouring the product into water. To purify it, it was 

 dissolved in benzene filtered from sodium acetate and the benzene removed 

 by distillation. It melted at 72°. The acetyl derivative was warmed with 

 methyl sulphate when the mixture heated spontaneously and on cooling 

 solidified to a pasty crystalline mass, which was drained on a porous plate. 

 The product, on boiling with cone, hydrochloric acid and evaporating, was not 

 the methochloride as it contained no chlorine, but probably undecomposed 

 methosulphate. When aminopyridine was heated in methyl alcohol solution 

 with 4 molecules of methyl iodide in the water-bath in a sealed tube for 

 6 — 7 hours, it was converted into the dimethylamino pyridine methiodide which 

 separated on evaporating the methyl alcohol in brown crystals of the periodide. 

 On dissolving the periodide in water iodine separated and the methiodide 

 passed into the solution, which is colourless. On evaporation under 

 diminished pressure the methiodide separated in fine, colourless needles which 

 turned yellow in the air. On analysis the compound gave 50 per cent, of 

 iodine (calculated for C 5 H 5 N (CH3) 2CH3I, I = 48 - l per cent.). The constitu- 

 tion is, therefore, represented by one of the following formulte : — 



Chemical Section. 



jN(CH 3 ) 2 -CH a I 



N 



/\ 

 CH 3 I 



* ' J. S. C. I. Ann. Report,' 1915, p. 863. 



