84 



REPORTS ON THE STATE OF SCIENCE. 



described by Crossley and Le Sueur in 1902, J and regards the acid as 

 3 : 5-dichloro-o-phthalic acid, although ' its constitution has never 

 been controlled.' 



3 : 5-dichloro-o-xylene has now been prepared from 3 : 5-dinitro-o- 

 xylene by means of the diazo reaction, and oxidised to 3 : 5-dichloro- 

 phthalic acid. A detailed comparison of the properties of these 

 synthetic products with those obtained as above mentioned from 

 dimethyldihydroresorcin shows them to be identical, as seen from the 

 following tabulated statement: — 



Dichloroxylene 



Dichlorodinitrox3'lene 

 Dichlorophthalic acid . 



Dicblorophthalic anhydride 

 Dichloropbthalanil 



From dimethyldihydro- 

 resorcin. 



Yellow, refractive liquid ; 

 slight aromatic odour. 

 B.p. 226°. m.p. 3-4°. 



M.p. 175-176°. 



M.p. 164° (previous soft- 

 ening) with evolution 

 of gas. 



M.p. 89°. 



M.p. 150-150°5. 



From 3 : 5-dinilro- 



c-xylerje. 



Yellow, refractive liquid ; 



slight aromatic odour. 



B.p. 226°, m.p. 5-7°. 



M.p. 176°. 



M.p. 164° (previous soft- 

 ening) with evolution 

 of gas. 

 M.p. 89°. 

 M.p. 150°. 



Hydro-aromatic ketones. 2 — In continuation of the work previously 

 described 3 1 : 1 : 2-trimethylcyclohexan-3-one lias been prepared from 

 trimethyldihydroresorcin as a starting point, the various steps involved 

 being indicated by the following formulae: — 



CH.C1I, H 2 C 



HO.C^s^ 

 CH 



H.C 



CO 



C(CH,\ 



H,0 



CH.CH, 



CO 



CH, 



H 2 C \ ./COOH 



(I) 



1-1 : 2-trimethyleyclohexan-3-one is a colourless liquid, boiling at 

 190°/750 mm., and when oxidised with potassium permanganate yields 

 8 -acetyl- c-meihylhexoic acid (I), which fact definitely establishes its 

 constitution. The investigation of this ketone is being continued, 

 partly on account of the similarity in (he groupings winch it contiins 

 with those of the camphor molecule. 



1 Trans., 81, 1533. a Unpublished work, 



8 Crossley and Reno'.if, J.C.S.. 1907, 91, C3. 



