268 



CYANOGEN COMPOUNDS 



[172 U-174. 



tube, gives hydrogen and ammonium 

 cyanides (Willm, Bull. Soc. [2] 41, 



449)- 



[V.] From methane [l] and nitrogen, 

 which give ammonium cyanide under 

 the influence of the silent electric dis- 

 charge (Figuier, Bull. Soc. [2] 46, 61). 



[W.] From succinic acid [Vol. II] 

 through acetylenedicarboxylic acid (see 

 under methane [l ; T]). The silver 

 salt of the latter on treatment with 

 strong nitric acid is decomposed with 

 the formation of silver cyanide. 



[X.] From fumaric acid [Vol. II] 

 through dibromsuccinic acid and acety- 

 lenedicarboxylic acid (see under me- 

 thane [l; II]), and then as above. 



[Y.] From methyl alcohol [13] through 

 methyl iodide and nitromethane (Bewad, 

 Journ. Russ. Soc. 24, 1 26 ; V. Meyer, 

 Ann. 171, 32). From the latter through 

 methazonic acid as above under J. Ni- 

 tromethane is also among the products 

 of interaction of dimethyl sulphate and 

 a nitrite (Kaufler and Pomeranz, Monats. 

 22, 492). 



[Z.] From ethylamine [Vol. II], 

 hydrogen cyanide being among the 

 products of pyrogenic decomposition 

 (Muller, Bull. Soc. [a] 45, 438). 



[AA.] From malonic acid [Vol. II] 

 and ethyl alcohol [14]. Ethyl malonate 

 on nitration gives a nitromalonic ester, 

 and this on heating with water at 160 

 yields hydrogen cyanide among other 

 products (Wahl, Comp, Rend. 132, 

 1050). 



[BB.] From glycerol [48] through 

 allyl alcohol (see under ethyl alcohol 

 (14 ; G]). The latter gives glyoxal by 

 ' contact ' oxidation over heated plati- 

 num (Trillat, Ctfmp. Rend. 133, 822). 

 From glyoxal as above under E. 



[CO.] From coumarin [Vol. II] 

 through coumarone (see under phlorol 

 [64 ; D]), and then through nitrocou- 

 marone as above under D. 



[DD.] From salicylic aldehyde [117] 

 and acetic acid [Vol. II] through 

 coumarone (see under phlorol [64 ; E]), 

 and then as above under D. 



[EE.] From cinnamic acid [Vol. II] 

 through coumarone (see under phlorol 

 [64; F]), and then as above. 



[FF.] From It/sine [Vol. II], hydrogen 



cyanide being among the products of 

 oxidation by barium permanganate 

 (Zickgraf, Ber. 35, 3401). 



[GG.] Urea [Vol. II] gives zinc 

 cyanide on heating with zinc dust 

 (Aufschlager, Monats. 13, 268). 



Organic Cyanides. 



NOTE : The cyanides of ally], benzyl, and 

 phenylethyl which, chiefly on the authority of 

 Hofmann (Ber. 7, 518 ; 520 ; 1293), are included 

 among the products contained in the oils of 

 black and white mustard seed and of various 

 cresses, are now known not to occur as such in 

 the plants, but to result as secondary products 

 of decomposition of the corresponding mustard 

 oils (Gadamer, Arch. Pharm. 237, in ; Ber. 

 32, 2336 ; Ter Meulen, Eec. Tr. Ch. 19, 37). 



173. Isocyanacetic Acid. 

 CN.CH 2 .COOH 



NATURAL SOURCE. 



This acid, on the authority of Calmels 

 (Bull. Soc. [a] 42, 266), is said to have 

 been found in toads. 



SYNTHETICAL PROCESSES. 



[A.] From acetic acid [Vol. II] by 

 the interaction of the bromo-acid and 

 silver cyanide [172] (Calmels, loc. cit.}. 



[B.] From glycocoll [Vol. II] by the 

 action of chloroform [l ; D] in presence 

 of caustic potash 



174. Thiocyanic Acid; 

 Snlphocyanic Acid. 



NC.SH 



NATURAL SOURCES. 



Allyl thiocyanate is possibly present 

 in traces with the isothiocyanate in 

 allyl mustard oil (see latter [166] for 

 natural sources: also Schmidt, Ber. 

 10, 187; Gildemeister and Hoffmann, 

 ' Die aetherischen Oele,' p. 53^)- 



Potassium thiocyanate occurs in the 

 urine of man, dogs, horses, and cattle, 

 and also in saliva and gastric juice. (For 

 occurrence in urine see Munk, Virchow's 



