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Chemistry. — "Action of Potassium hypochlorite on Cinnamide" . 

 By Dr. R. A. Weerman (Communicated by Prof. Hoogewerff). 



(Communicated in the meeting of September 29, 1906). 



From the experiments of Baucke ^) on propiolamide and those of 

 Freundler ^), VAN LiNGE ') and Jeffreys '') on cinnamide it appears 

 that in the case of these unsaturated acids, the Hofmann reaction 

 to prepare an amine from an amide by means of a halogen and an 

 alkali does not succeed. 



As to the non success we may form two hypotheses: lirst of all 

 that the double bond *) prevents the intramolecular rearrangement of 

 atoms which must be assumed in the Hofmann reaction, and secondly 

 that the amine supposed to be formed, in this case CgH.CH z=CHNH,, 

 suffers decomposition under the said circumstances. ®). 



The first, however, is 7iot the case as from cinnamide may be 

 prepared the urea derivative : 



C,H,Cii3=:Cn— N" 



C,HAi=Ch-Co-Nh 

 where consequently one-half of the amide has undergone the trans- 

 formation. 



This being a case of an unsaturated amide, it is necessary to make 

 use of the modification proposed by Hoogewerff and van Dorp and 

 not to work with free halogen. Further the hypochlorite solution 

 must not contain any free alkali ; on account of the insolubility of 

 cinnamide and the consequent inertness, an alcoholic solution is 

 employed. 



Although at first sight it appears strange that in alcoholic solution 

 the urea derivative is foi"med and not the urethane, this may be 

 explained by the experiments of Stieglitz and Earle '), which show 

 that isocyanates react very readily with halogen-amides ®). 



1) Rec. 15, 123. 



2) Bull [3] 17, 420. 



5) Dissertation van linge, Bazel 1896. 

 ^) Am. Ghem. Journ. 22, 43. 



°) On account of the great analogy existing between the Lossen transformation 

 of hydroxamic acids and the Hofmann reaction, this first supposition was not very 

 probable, as Thiele had prepared from the acylated cinnamohydroxamic acid the 

 urethane GgHjCil —C^l — N'^— G'^oGsH-. A second indication, though less conclusive, 

 in the more distant analogy between the Beckmann rearrangement and the 

 Hofmann reaction was the formation of isochinolin from the oxime of cinnamaldehyde. 

 (Ber. 27, 1954). 



6) Thiele, Ann. 309. 197. 



') Am. Ghem. Journ. 30, 412. G 1904, I, 239. 



^) This is the reason why, in the preparation of urethanes according to Jeffreys, 

 the sodium elhoxide should be added all at once. 



