PHENACETIN. 43 



an aniido group in the presence of another compound containing the 

 same group, even though one is more readily su-trd on by tin- :i^vnt> 

 employed than the other. The test is applied by heating together for 

 a few minutes about 0.5 gram of the MibManre and 5 cc of a 10 per 

 cent solution of sodium hydroxid, then cautiously adding a few drop- 

 of chloroform and setting the mixture aside for a few minutes. If a 

 primary amine is present the characteristic offensive odor of phen\ I 

 carbamine can readily be detected. This reaction has received ollicial 

 sanction in the pharmacopeias of the United States, England, and 

 Germany, and is so frequently cited as suitable for detecting acetan- 

 ilid in phenacetin that a short resume of some of the misleading state- 

 ments made concerning it is desirable. 



CONFLICTING STATKMKNTS KK<;.\KI>IN< TIIK ISONITRIL KKACTION. 



As early as 1887 Utescher" found that after heating phenacetin, 

 sulphuric acid, and alcohol together, rendering the mixture distinctly 

 alkaline with a fixed alkali, and adding a few drops of chloroform, the 

 repugnant odor of carbylamine was developed. The sulphuric acid 

 probably decomposes the phenacetin into acetic acid and phenetidin 

 (C 6 H 4 NH 2 OC 2 H 5 ). 6 Schwartz^ states that a simple method for deter- 

 mining acetanilid in phenacetin is by means of the isonitril reaction. 

 W. Lenz, d in his review of special analytical methods, says that it is 

 self-evident that for the detection of acetanilid in phenacetin the well- 

 known ''isonitril reaction" can be employed. Again, this author 

 states that a mixture of acetanilid and phenacetin will give the "isoni- 

 tril reaction." C. Platt* says: 



Another test useful also in detecting small quantities of acetanilid in the presence 

 of phenacetin is to treat the mixture with caustic soda or potash in the presence of 

 chloroform, when, if acetanilid be present, the characteristic odor of isonitril is 

 given off. If phenacetin be heated with alcohol and sulphuric acid the character- 

 istic odor of ethyl acetate is observed; by heating the solution thus formed with 

 caustic potash and chloroform, the carbylamine reaction is obtained. 



In an article entitled " Adulteration and Substitution of Drugs," by 

 Schweitzer/ the following statements arc found: 



Acetanilid is identified * * * by heating 0. 10 gram of the powder with 1 cc of 

 NaOH (15 per cent NaOH) and three drops of chloroform, whereupon the offensive 

 smell of phenyl-isocyanide is given off. * * * For the identification of the mix- 

 ture (acetanilid and phenacetin) it is sufficient to state that the substance begins to 

 melt at 92 C. and becomes completely transparent below 134 C. On heating 0.10 

 gram of powder with 1 cc of caustic soda (15 per cent NaOH) and 3 drops of chloro- 

 form the offensive smell of phenyl-isocyanide is observed. 



a Apoth. Ztg., 1887, 2: 436, through J. Soc. Chem. Ind., 7: 227. 



&Ann. (Liebig), 1899, 309: 233. 



cPharm. Ztg., 1888, 83: 357. 



dZtschr. anal. Chem., 27: 665. 



* J. Anal. Appl. Chem., 1893, 7: 77. 



f J. Soc. Chem. Ind., 1895, 14: 852. 



