N-Butylmalonic ester

Problem 16.19 Prepare n-hexyl chloride from n-butylmalonic ester. ... 

Alkylation of enolates. Determination of the rate constants for alkylation, for example of sodio-n-butylmalonic ester with n-butyl bromide in benzene solution in the presence of various additives, showed that at a concentration of less than 5% tetramethylurea increases the reaction rate many fold. Dimethylformamide was slightly more effective, but higher yields are reported when tetramethylurea was used. 

Alkylation and nitration of malonic esters. Zaugg, using sodium hydride for conversion of n-butylmalonic ester into its sodio derivative, found that the rate of alkylation of this substance with -butyl bromide in dimethylformamide is 1,000 times the rate in benzene. Emmons and Freeman developed a procedure for the nitration of active methylene compounds with acetone cyanohydrin nitrate by conversion to the sodio derivative with sodium hydride. The reaction product (3)... 

Into a 2-litre, three-necked flask, fitted with a separatory funnel, a mechanical stirrer and a reflux condenser, place a hot solution of 200 g. of potassium hydroxide in 200 ml. of water. Stir the solution and add slowly 200 g. of ethyl n-butylmalonate (Section 111,154). A vigorous reaction occurs and the solution refluxes. When all the ester has been added, boil the solution gently for 2-3 hours, i.e., until hydrolysis is complete a test portion should dissolve completely in water. Dilute with 200 ml. of water and distil oflF 200 ml. of liquid in order to ensure the complete removal of the alcohol formed in the hydrolysis (1) it is best to connect the flask by means of a wide delivery tube to a condenser set for downward distillation (compare Fig. II, 41, 1 but with a mercury-sealed stirrer in the centre neck). Replace the separatory funnel and the reflux condenser. 

Dicyclohexylcarbodiimide n-Butylmalonic acid ethyl ester Hydrazo benzene... 

A mixture comprising 108 g of phenyl hydrazine and 216 g of the diethyl ester of n-butylmalonic acid is heated on an oil bath at 170°-180°C for 12 hours. The residue is taken up with water in which an alkaline compound has been dissolved and acetic acid is added to precipitate 4-n-butyl-2-phenyl-pyrazolidine-3,5-dione. The product is a white crystalline solid having a MP 103°C. It is soluble in acetone and benzene, soluble in hot condition in methanol and ethanol and insoluble in water. 

Claisen Condensation Reparation of Ethyl Cinnamateand Cinnamic Acid 9-16. Malonic Ester Synthesis—Preparation of Ethyl-n-Butylmalonate... 

Monoalkylation of malonic ester occurs with primary and some secondary halides in 75-90% yield [16]. An example of the reaction is given for the preparation of ethyl n-butylmalonate [16]. 

Malonic Ester Synthesis—Preparation of Ethyl-n-Butylmalonate 16 ... 

The ethyl sec,-butylmalonate was prepared from sec-butyl bromide and malonic ester according to the general method described in Org. Syn. 4, n. The yield of ester boiling at i24-i32°/28 mm. was 80-81 per cent of the theoretical amount. The yields of 3-methyl pentanoic acid given in this procedure were obtained with this grade of ester. 

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