Ryan and Pluxkett — On Unsaturated fi-Diketones. — III. 203 



3. Methyl-S'i-di'methoxyciniiamoi/l-pyriivate. 

 (CB*0>C 6 H 3 CH : CH . CO . CH, . CO . COOCH, 



A mixture of 20 grams of veratrylidene-acetone and 30 grams of dimethyl 

 oxalate was heated in a small dry flask until it had melted ; five grams of 

 sodium wire were added, and the mixture was warmed until an energetic 

 reaction commenced. When the reaction had subsided, about 50 c.cs of 

 anhydrous ether were added, and the flask, protected from atmospheric 

 moisture, was let stand for twenty-four- hours. The excess of sodium 

 was removed by addition of moist ether. The sodium derivative of the 

 diketone was dissolved in 100 c.cs of water : the alkaline aqueous layer was 

 separated and acidified with dilute hydrochloric acid. The diketone was 

 extracted with chloroform. The chloroform solution was shaken with dilute 

 sodium bicarbonate, separated, and passed through a dry filter paper. On 

 addition of alcohol to the concentrated chloroform solution, the diketone 

 separated in orange-yellow crystals, which, when dried, melted at 121 C -122°C., 

 and gave on analysis the following result : — 



0-2172 substance gave 0-4888 CO, and 0-1122 H 2 

 corresponding to C 61-37, H 5*7 

 C i5 H 16 6 requires C 61-64, H 5o. 

 Methyl 3'i-dimettoxycin/iamoyl-pyruvate crystallizes from alcohol in 

 orange-yellow plates, which are sparingly soluble in cold alcohol, soluble in 

 ether or benzene, and readily soluble in chloroform. Its solution in ether or 

 chloroform has a strong green fluorescence. 



A solution of the substance in boiling alcohol gives a dark-brown 

 coloration with ferric chloride. 



The crystals are coloured dark violet on contact with concentrated 

 sulphuric acid, in which they dissolve, forming a violet-coloured solution. 



When mordanted wool is boiled with a solution of the substance in diluted 

 alcohol, the following shades are obtained : — 



Mordant Colour 



Aluminium Sulphate, . . Deep yellow 

 Potassium Dichromate. . Chocolate-brown 



Stannous Chloride, . . Bright orange 

 Ferric Sulphate, . . . Dark olive-brown 



3. Ethyl o'^Dimethoxy^-Ciwiw.nwnyl-Isofazol-a-Carooxylate. 



CH 

 /\ 

 (CH 3 0)jC s Hs . CH : CH . C / X C . COOCsHe 



w 



N O 



