Ethyl acetoacetate, aluminum derivative

The aluminum derivative of ethyl acetoacetate has been prepared by the reaction of aluminum ethoxide with ethyl acetoacetate, by the reaction of amalgamated aluminum metal with ethyl acetoacetate, and by the reaction of potassium aluminate with ethyl acetoacetate. The present synthesis is a modification of the first method. 

Thirty-three grams (0.19 mol) of aluminum ethoxide is vacuum-distilled into a 250-ml. round-bottomed flask, and 80 g. (0.6 mol) of vacuum-distilled ethyl acetoacetate (59.8° at 8 mm.) is added. Other aluminum alkoxides cannot be substituted successfully for aluminum ethoxide in this synthesis since some substitution of the alkyl group of the alk-oxide, for ethyl, appears to occur in the resulting aluminum acetoacetate derivative. The flask is fitted with a reflux condenser, and the mixture is heated gently with an oil bath the temperature is raised gradually from 85 to 140° over a period of 4 hours. The aluminum ethoxide dissolves slowly as the reaction proceeds, and the ethyl alcohol formed is distilled off at 170° and 25 mm. (A considerably lower temperature can be used if a better vacuum source is available.) At the end of 4 hours the product is cooled to room... 

The aluminum derivative of ethyl acetoacetate is a white crystalHne material, reported to melt at 76°, or 78 to 79°. It supercools readily from the melt to a straw-colored, very viscous liquid. Molecular weight determinations in carbon disulfide indicate that the compound is not associated in that solvent. The aluminmn derivative of ethyl acetoacetate is very soluble in benzene, ether, and carbon disulfide. It is less soluble in petroleum ether or cyclohexane and is insoluble in water. The compound boils at 190 to 200° at 11 mm. The reported dipole moment, in benzene, is 3.96 Debye. Surface tension and density values for the liquid above the melting point have been reported by Robinson and Peak. ... 

Al(CeH908)s Aluminum derivative of ethyl acetoacetate, 9 25 AlClj, 7 167... 

Aluminum trichloride exhibits several unique characteristics as a promoter of the Pechmann condensation. Not only does AICI3 lead to significantly enhanced yields in condensations that proceed either poorly or not at all in sulfuric acid (e.g., the synthesis of 4-methylcoumarin from phenol and ethyl acetoacetate j but AICI3 also exerts an unusual influence on the regiochemical outcome of the condensation of resoreinol derivatives and P-keto esters. Whereas other condensing agents favor the formation of... 

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