Dimethyl hendecanedioate

Dimethyl hendecanedioate is prepared by heating 23 g. (0.106 mole) of hendecanedioic acid 2 under reflux for 2 hours with a solution of 8 ml. of concentrated sulfuric acid in 80 ml. of methanol. After the reaction mixture has been diluted with 3 volumes of water, it is extracted with two 75-ml. portions of benzene. The benzene extracts are washed successively with 250-ml. portions of water, 5% aqueous sodium carbonate solution, and... 

The submitters state that the residue may be distilled to give dimethyl hendecanedioate in 98% yield (25.5 g.). 

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