( 141 ) 



Piperidine (10 grams) with allyl formate (14 grams) gives a rise 

 from 10° to 83°, and a very good yield of the foi-myi derivative, 

 b.p. 220°. 



The boiling points of the substituted formamides exhibit peculiar 

 regularities to which I hope to refer later on. 



The dialkvlformamides and formylpiperidine have acquired some 

 importance owing to the interesting researches of Bouveault ^), who 

 used them as a starting point in the preparation of aldehydes ; the 

 above described simple methods of preparation may perhaps prove 

 to be of service. 



Chemistry. — ''On the action of hydrocyanic acid on ketones''. 

 By A. J. Ultee. (Communicated by Prof. P. van Romburgh). 



Although it is stated in every textbook on organic chemistry that 

 ketones may combine with hydrocyanic acid, the conditions under 

 which this addition takes place have up to the present not been 

 studied, and only those few cyanohydrins which are solid and may 

 consequently be readily puritied by recrystallisation have been isolated 

 in a pure condition^). 



Three methods of formation of these substances are known : 



1^*. Action of dilute or anhydrous hydrocyanic acid on ketones, 

 either by heating the mixture for some hours in scaled tubes at 100° 

 or by simply leaving the two components in contact with each other 

 at the ordinary temperature for several months. 



2"^^. Action of nascent hydrogen cyanide on ketones, for instance 

 by very slowly dropping fuming hydrochloric acid on potassium 

 cyanide covered with acetone. 



3''^. By double decomposition of the so-called bisulphite compounds 

 of the ketones with a solution of potassium cyanide. 



A closer study of the nitriles of the oxy-acids was made in conse- 

 quence of an observation made by Prof, van Romburgh ^) as to the 

 action of solid potassium carbonate on a mixture of dry acetone and 

 hydrocyanic acid ; a small quantity of this salt caused the mass to 

 boil and the temperature to rise to 70°. 



The same phenomenon is caused by potassium hydroxide, potassium 

 cyanide, ammonia, amines, in fact by all substances whose aqueous 



1) Bull. Soc. chim. [3] 31, 1322. 



2) Acetonecyanohydrin, obtained from KaLlbaum, seemed to contain much free 

 hydrocyanic acid. 



s) Meeting 27 June 1896. 



10* 



