PP-Dimethylacrylic acid

This reaction illustrates the conversion of the —COCH3 group into the —COOH group by means of a hypohalite  

Fit a 1-litre three-necked flask with two double surface condensers and a glycerine-scaled stirrer (Fig. II, 7, 10). Place 25 g. (29 ml.) of mesityl oxide (Section 111,79), 50 ml. of dioxan and a cold (10°) solution 

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PP-Dimethylacrylic acid, 460 Dimethylamine hydrochloride, 414, 416 Dimethylaminomethylindole, 1012,1013 P-Dimethylaminopropiophenone hydrochloride, 910, 911... 

Into a 500 nil. round-bottomed flask, provided with a double surface condenser, place 50 g. (63 ml.) of pure, dry acetone, 50 g. (47 ml.) of ethyl cyanoacetate (Section 111,131) and 0 -5 g. of piperidine. Allow to stand for 60 hours and heat on a water bath for 2 hours. Treat the cold reaction mixture with 100 ml. of ether, wash with dilute hydrochloric acid, then with water, and dry over anhydrous sodium or magnesium sulphate. Distil under diminished pressure and collect the ethyl fsopropylidene cyanoacetate (ethyl a-cyano-pp-dimethylacrylate) at 114-116°/14mm.(l). The yield is 39 g. 

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