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ChemicalBook CAS DataBase List Acetylenedicarboxylic acid
142-45-0

Acetylenedicarboxylic acid synthesis

8synthesis methods
-

Yield:142-45-0 71%

Reaction Conditions:

with sodium hydroxide;sodium hypochlorite;4-acetylamino-2,2,6,6-tetramethyl-1-piperidinoxy in water; pH=8.5 - 10 at 5 - 10;

Steps:

8 Example 8; Oxydation of 2-butine-1,4-diol to acetylene-dicarboxylic acid in an aqueous monophasic system using acetamido-TEMPO
[0186] 14.4 g (167 mmol) of 2-butyn-1,4-diol are dissolved together with 2.14 g (10.0 mmol) of 4-acetamido-TEMPO in 94 ml of water (reaction component 1). [0187] 6.68 g (167 mmol) of NaOH are dissolved in 337 ml (0.741 mol) of sodium hypochlorite solution (approx. 2.2 M technical bleaching liquor; pH 14) and cooled to 5° C. (reaction component 2). [0188] A flask equipped with mechanical stirrer is initially charged with 50 ml of water and cooled to 3° C. Reaction components 1 and 2 are added in parallel with good stirring and cooling in such a way that the internal temperature does not rise above 10° C. During this time, the pH of the reaction mixture is kept in the range from 8.5 to 10 by adding 20% sodium hydroxide solution. A total of approx. 15 ml of sodium hydroxide solution are consumed. [0189] On completion of addition, stirring is continued for another 20 min. [0190] The reaction mixture contains 11.4 g of acetylene-dicarboxylic acid in solution and 2.1 g of acetylene-dicarboxylic acid in the precipitate formed (overall yield 13.5 g, 71%). Extraction is effected using 300 ml of MTBE, then the pH of the aqueous reaction mixture is adjusted to pH 0 with stirring in an ice bath using conc. sulfuric acid, and extraction is effected by shaking 3 times using 100 ml of MTBE each time. The MTBE extracts of the acidic reaction mixture are concentrated by evaporation. 11.1 g of acetylenedicarboxylic acid are obtained in the form of a colorless solid.

References:

Consortium Fur Elektrochemische Industrie GmbH US2004/59154, 2004, A1 Location in patent:Page 8-9

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