— 103 — 



in acetic acid solution into a-isopropy\-y- acetyl butyric acid (methyl-2- 

 heptanone-6-carboxylic-3-acid), a body also hitherto unknown, and further, 

 by alkaline bromine liquor, into «-isopropylglutaric acid (m. p. 94 to 95°), 

 a body originally prepared by Perkin jun. 1 ). 



The quantity of keto-acid obtained from the hydroxy-methyl-isopropyl- 

 adipic acid was too small for fractionation. The semicarbazone had a 

 m. p. of 158 to 159°. 



0,1185 g. subst.: 0,2259 g. C0 2 , 0,0934 g. H 2 0. 



Found Calc. for Ci H 19 N 3 O 3 



C 52,01 °/o 52,36 °/o 



H 8,75 °/o 8,35 °/o. 



The formula of the acid is therefore C 9 Hi O 3 , and it results from a 



CH 3 

 hydroxybicarboxylic acid by the oxidation of a RCCOOH-group into a 



OH 



RCO-CHs-group. 



The presence of the CO-CH 3 -group was evident from the behaviour 

 of the keto-acid towards 4°/o alkaline bromine-liquor (1,1 cc. bromine to 

 1 g. acid) with which the acid was shaken at a low temperature for one 

 day. In the course of this treatment the methyl group was split off under 

 formation of bromoform, the carbonylic residue being oxidised into carbo- 

 xyl. The acid, when liberated from the alkaline solution by sulphurous 

 acid and dilute sulphuric acid, melted, after being recrystallised from 

 water, at 91 to 93°. 



0,1201 g. subst.: 0,2436 g. C0 2 , 0,0835 g. H 2 0. 



Found Calc. for C 8 Hi 4 4 



C 55,32°/o 55,17°/o 



H 7,72 °/o 8,04 °/o. 



Titration with semi-normal potash liquor showed the acid to be dibasic. 

 It proved to be identical with «-^opropyl glutaric acid, m. p. 94 to 95°. 

 For further identification we converted the acid by heating 0,4 g. (dissol- 

 ved in chloroform) with 1 mol. acetyl chloride into its anhydride, which 

 separated out from light petroleum in long needles, melting at 52 to 54°. 

 Adding freshly-distilled aniline to the anhydride dissolved in light petroleum 

 we converted it into the anilide which, in agreement with the experience 

 of Perkin, melted at 156 to 158°, becoming deliquescent before reaching 

 the m. p. 



a-Zsopropylglutaric acid, the identity of which has been sufficiently 

 established by the tests mentioned above, had also been generated directly 



2 ) Journ. chem. Soc. 69 (1896), 1495. 



