520 Scientific Proceedings, Royal Dublin Society. 
It was supposed by Gabriel that the amidoketones, although 
unstable in the free state, could exist in the form of stable salts, 
such as the hydrochloride. This was confirmed by his experi- 
ments and those of his pupils.’ 
I have prepared two new members of the series, and examined 
some of their properties and reactions. 
In doing so I have used two distinct methods with the object — 
of finding by what procedure this very interesting but difficultly 
accessible group of bodies may be most readily obtained for 
synthetical purposes. 
First Method of Preparing Amidoketones.—Xylyl bromide, 
treated with acetoacetic ester and sodium alcoholate, was con- 
verted into xylylacetoacetic ester. By the action of nitrous 
acid on substituted acetoacetic esters of the fatty series, Victor 
Meyer and his pupils’ obtained, with yields of from 30-50 per 
cent., the simpler members of the isonitrosoketone series. For the 
higher fatty members, the yield was considerably poorer. In the 
aromatic series, Ceresole made isonitrosobenzyl acetone from the 
barium salt of benzylaceto-acetic acid by the action of nitrous 
acid, but the yield was poor. 
With no better result I have prepared m-xylyl-isonitroso- 
acetone by the method used by Victor Meyer for the fatty series. 
The low yield is mainly due to the slowness with which 
xylylacetoacetic ester dissolves in dilute potassium hydrate and the 
consequent decomposition of some of the already dissolved ester 
due to the prolonged standing of the alkaline solution. Moreover, 
oily by-products diminish the return of the pure product, which 
in the most favourable cases was only about 25 per cent. 
The use of a shaking machine for producing the solution did 
not materially improve the yield. 
The reduction of the i-nitrosoketone to the amido compound 
gave a yield of about 50 per cent. of the theoretically expected 
amount of the hydrochloride of the amidoketone. 
Still the many operations necessary for the production of 
metaxylyl amidoacetone from metaxylene render the final yield 
very poor, which was only about 4 per cent. of the theoretical. 
1 Ber, 26 (1893), p. 2199 ; 27 (1894), pp. 1037, 1141; 28 (1895), pp. 1513, 2036; 
29 (1896), p. 2603; 30 (1897), p. 1515. 2 Ber. 11 323, ete. 
