738 URINE. 



An oxidation in the side chain of aromatic compounds is often found, 

 and may also occur in the nucleus itself. As an example, benzene is first 

 oxidized to oxybenzene (SCHULTZEN and NAUNYN), and this is then 

 further in part oxidized into dioxybenzenes (BAUMANN and PREUSSE). 

 Naphthalene appears to be converted into oxy naphthalene, and probably 

 a part also into dioxynaphthalene (LESNIK and M. NENCKI). The hydro- 

 carbon with an amino- or imino-group may also be oxidized by a sub- 

 stitution of hydroxyl for hydrogen, especially when the formation of a 

 derivative in the para-position is possible (KLINGENBERG) . For example, 

 aniline, C 6 H 5 .NH2, passes into paraminophenol, which latter passes into 

 the urine as its ethereal-sulphuric acid, H 2 N.C 6 H 4 .O.SO2.OH (F. MULLER). 

 Acetanilid is in part converted into acetyl paraminophenol (JAFFE and 

 HILBERT, K. MORNER), and carbazol into oxycarbazol (KLINGENBERG). 1 



An oxidation of the side chain may occur by the hydrogen atoms being 

 replaced by hydroxyl or may also take place with the formation of carboxyl ; 

 thus, for example, toluene, C 6 H 5 .CH 3 (SCHULTZEN and NAUNYN), ethyl- 

 benzene, C 6 H 5 .C 2 H5, and propylbenzene, C 6 H 5 .C 3 H 7 (NENCKI and GiACosA), 2 

 besides many other bodies, are oxidized into benzoic acid. Cymene is 

 oxidized to cumic acid, xylene to toluic acid, methylpyridine to pyridine- 

 carboxylic acid in the same way. If the side chain has several members, 

 the behavior is somewhat different. Phenylacetic acid, C 6 H 5 .CH 2 .COOH, 

 in which only one carbon atom exists between the benzene nucleus and 

 the carboxyl, is not oxidized, but is eliminated after conjugation with 

 glycocoll as phenaceturic acid (SALKOWSKI 3 ) . Phenylaminoacetic acid, 

 C 6 H 5 .CHNH 2 .COOH is in part converted into mandelic acid (phenyl- 

 glycollic acid), C 6 H 5 .CHOH.COOH, and in great part is eliminated as 

 such (SCHOTTEN, KNOOP 4 ). Phenylpropionic acid C 6 H 5 .CH 2 .CH 2 .COOH, 

 with three carbon atoms in the side chain, is, on the contrary, oxidized 

 into benzoic acid, and H. and E. SALKOWSKI 5 have proposed the rule that 

 the homologues of the benzoic acids are converted into benzoic acid when 

 the side chain contains more than two carbon atoms. 



KNOOP 6 has shown by experiments with several acids, that this rule 



1 Schultzen and Naunyn, Arch. f. (Anat. u.) Physiol., 1867; Baumann and Preusse, 

 Zeitschr. f. physiol. Chem., 3, 156. See also Nencki and Giacosa, ibid., 4; Lesnik and 

 Nencki, Arch. f. exp. Path. u. Pharm., 24; F. Miiller, Deutsch. med. Wochenschr., 

 1887; Jaff^ and Hilbert, Zeitschr. f. physiol. Chem., 12; Morner, ibid., 13; Klingen- 

 berg, " Studien iiber die Oxydation aromatischer Substanzen," etc., Inaug.-Diss. 

 Rostock, 1891. In regard to formanilid, which acts essentially as acetanilid, see 

 Kleine, Zeitschr. f. physiol. Chem., 22. 



2 Zeitschr. f. physiol. Chem., 4. 



3 Ibid., 7 and 9. 



4 Ibid., 8. 



5 Ibid., 7. 



6 Hofmeister's Beitrage, 6, and Habilit.-Schrift, Freiburg, 1904. 



