200 Mr Ruhemann, Dithioxanthoxalanil and its Homologues. 
Of great interest is the action of reducing agents on dithio- 
xanthoxalanil, which differs from the behaviour of xanthoxalanil 
and its homologues towards zinc dust and acetic acid (see S. Ruhe- 
mann, Trans. Gliem. Soc. 1906, lxxxix. 1847). 
The latter substances thus add six atoms of hydrogen and 
yield colourless compounds, but dithioxanthoxalanil is transformed 
into a substance with the formula C 20 H lfi O 3 N 2 . In this case, 
therefore, no addition of hydrogen takes place ; instead of it, the 
total sulphur is replaced by hydrogen. The facts that this 
substance is colourless and insoluble in sodium carbonate, lead 
to the conclusion that the substitution is accompanied by a change 
of the linking, and that the constitution of C 2n H lf) 0 3 N 2 is probably 
to be represented thus : 
/OH,- CH CO — CCk 
c g h 5 .n<^ II I >N.c 6 H 5 . 
x CO — C — CH — CH/ 
On boiling this compound with sodium carbonate, it is trans- 
formed into the blue sodium derivative of a red substance, which 
latter is formed on adding an excess of hydrochloric acid to the 
blue salt. The behaviour of the red compound — this is most 
likely isomeric with the reduction product O 20 Hi 6 O 3 N 2 of dithio- 
xanthoxalanil — resembles the red isomeride C 14 H 12 0 3 which Ruhe- 
mann and Merriman (Trans. Chein. Soc. 1906, lxxxix. 1886) 
obtained in the course of the study of the reaction between 
phenylpropiolyl chloride and acetylacetone. This, also, forms 
blue salts, as does Claisen and Ewan’s oxalyldibenzylketone. 
This resemblance leads to the view that those compounds have 
to be represented by similar structural formulae. Experiments 
are in progress with the object of verifying this conclusion. 
