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COT at Seen ys 
THE STUDY OF HYDRO-AROMATIC SUBSTANCES. 147 
100° respectively, the latter is probably a mixture of isomeric trimethyl- 
cyclohexenones. Dimethylethyl- and dimethylpropylcyclohexenones 
have also been prepared by the condensation of chlorodimethylcyclo- 
hexenone with substituted malonic esters; but as the yields of con- 
densation products diminish rapidly with increase in molecular weight 
of the substituted malonic ester employed, the reactions are of no great 
value for the production of the higher homologues of isophorone. 
3. The so-called 1:1-dimethyl- A2:5-cyclohexadiene of Harries and 
Antoni. 
A further inquiry into the properties and behaviour of the 
1:1-dimethylcyclohexadiene of Harries and Antoni has shown that 
this hydrocarbon is a mixture of the 1:2- and 1 :3-dimethyleyclo- 
hexadienes, and very probably contains none of the isomeric hydro- 
carbon with the two methyl groups in the 1 : 1-position. 
Incidentally it has also been noted that the 1: 3-dimethyleyclo- 
hexadiene, prepared by the dehydration of methylheptenone, is a 
mixture of m-xylene, 1: 3-dimethylcyclohexene and 1: 3-dimethylcyclo- 
hexadiene. 
The Transformation of Aromatic Nitroamines and Allied Substances, 
and its Relation to Substitution in Benzene Derivatives.—Report of 
the Committee, consisting of Professor F. 8S. K1pping (Chairman), 
Professor K. J. P. Orton (Secretary), Dr. S. RUuHEMANN, Dr, 
A. Lapworts, and Dr. J. T. Hewitt. 
I. Transformation of Nitroaminobenzenes into Nitroanilines. 
In last year’s Report ?a summary was given of the study of the conditions 
under which nitroaminobenzenes change into nitroanilines. It was shown 
for solutions of nitroamines, (i) that all acids accelerate (or initiate) the 
‘change ; (ii) that the efficacy of different acids bears a relation to their 
activities in other reactions ; (iii) that the rate of change is proportional 
to the square of the concentration of the acid ; (iv) that the transforma- 
tion was always accompanied by the appearance of nitrous acid, and the 
conversion of nitroamine into diazonium salt. 
Il. Transformation of Chloroaminobenzenes into Chloroanilides, 
(With W. C. Evans, B.Sc., and W. J. J ONES, B.Sc.) 
The results obtained in the case of the nitroamines have led us to make 
a study of the similar transformation of acylchloroaminobenzenes into 
chloroacetanilides : C;H;NCl.Ac>Cl.0,H,.NH. Ac. 
This change offers a very marked contrast to that of the nitroamino- 
benzenes, as hydrochloric acid appears to occupy a peculiarly privileged 
position, which was originally recognised by Armstrong, in bringing 
about this change. 
Crossley and Renouf, .7.C.8., 1909, 95, * B.A. Report, 1908, p. 115, 
les 
