

— 127 — 



is abstracted from the aqueous liquid by repeatedly extracting with 

 ether. It is clear from the following results of this work that the 

 oxalic acid ester enters the methylhexanone in para-position towards 

 the methyl-group, and that consequently methyl- i-hexanone-3 -oxalic 

 ester-4 has been formed. The condensation-product gives a dark-brown 

 coloration in alcoholic solution with ferric chloride. Concentrated soda 

 liquor splits up the ester into methyl hexanone and sodium oxalate. 

 With ammonia it also reproduces the ketone and oxamide. The crude 

 condensation product yields with copper acetate a bright green copper 

 salt, which melts at 153 . The pure ester separated from the copper 

 salt by dilute sulphuric acid boils at 163 (12 to 13 mm. pressure); 

 di5° 1,0903. Its semicarbazone melts above 245 . Dilute sulphuric 

 acid or soda liquor saponify it readily into methylhexanone oxalic acid 

 which melts at 13 2 . When heated with aniline in a water bath, the 

 ester forms a pyrrolidone derivative of the formula C 21 H 20 ON 2 . When 

 distilled at atmospheric pressure, it is converted with loss of carbonic 

 oxide into methyl- 1- hexanone- 3 -carboxylic ester-4, a mobile liquid of 

 the boiling point 128,5° ( r 5 mm - pressure); d^o 1,057. Its copper 

 salt melts at 155°. With phenylhydrazine the ester yields a pyrazolone 

 of the melting point 243° to 245°; with ammonia tetrahydromethyl 

 anthranilic acid ester of the melting point 67°. The corresponding 

 methyl ester stands, according to the odour, in no relation whatever 

 to methyl ester of methyl anthranilic acid. With suitable treatment 

 with methyl iodide and a solution of sodium in methyl alcohol, methyl- 

 hexanone carboxylic ester is converted into methyl- i-hexanone-3 -methyl- 

 4-carboxylic ester-4. The specific gravity of the ester boiling at 120° 

 to 122° (12 mm. pressure) is 1,0189 (19°). The isopropyl ester 

 constituted in an analogous manner boils at 135 to 137 (10 mm. 

 pressure); d^o = 1,009. ^ ts semicarbazone melts at 144° to 145°. 

 When splitting up the ketone with concentrated methylalcoholic potash 

 there is formed the natural d-menthone of the boiling point 206° 

 to 208°; di 8 o 0,898; [a]© -f- 11,68°; the corresponding semicarbazone 

 melts at 184 to 185°. As in this case the specific rotatory power 

 ([ a Jr>— |— 28,14°) is only about half as large as that of the d-menthone 

 which can be obtained from natural 1-menthone by inversion with 

 concentrated sulphuric acid, it may be assumed that in the case before 

 us, lsevorotatory menthone is present in addition to a preponderance 

 of dextrorotatory menthone. On reduction with sodium and alcohol, 

 ; only lsevorotatory menthone is formed, of which one fraction boils 

 at 214° to 216°, and congeals into crystals melting at 37°. The other 

 fraction of the boiling point 212° to 214° can only be obtained 

 crystallised by continued cooling. The urethanes of both menthols 

 melt at 111°, like that of natural menthol. The formation of the 

 ordinary para-menthone has proved that the above condensation product 



