THE ALUMNI JOURNAL. 



derivative (CoHsXo) is capable of existing 

 in three modifications, their isomerism, 

 being due to the relative position of the 

 two substituting groups. Thus di deriva- 

 tives are known in three modifications, 

 and no more. These are designated by 

 the terms 



C.,H.N,,H: 





ORTHO 



1-2 



iC. HJ 



-/ 



META 

 1-3 



la, HJ 



la H, 



PARA 



1-4 ^i-^ 

 substitution being affected respectively, 

 in two adjacent, intermediate or opposite 

 carbon atoms, giving rise to products 

 that differ greatly in chemical and phar- 

 macological action. 



By action of nitric acid on benzene we 

 obtain a nitro-derivative (C,-,H--NO.j) 

 called oilofmirbane, by reduction of this 

 we obtain amido benzene or a«////Z(?(C6H5- 

 NH2). If one of the hydrogens in the 

 amido group of anilin be substituted by 

 the acetyl radical (CH3-CO), we obtain 

 antifebriii (acetanilid C6H5-NH-CH3-CO). 

 If we replace one hydrogen in the nucleus 

 of acetanilid by bromine, brom-acetanilid 

 or antisepsin results. If the other hydro- 

 gen of the amido group in acetanilide is 

 replaced by the methyl radical, exalgin 



CH, 

 CH— CO 



is obtained, an antineuralgic. Substitu- 

 ting one hydrogen of the amido group in 

 anilin by the benzoyl radical (CgH-CO) 

 benzanilid (C,H5-NH-C,H,-C0) an anti- 

 pyretic, results. 



By the introduction of a second amido 

 group in place of a H atom in anilin we 

 ohtdXw phenyl-hydrazine (S^.^.^-'^YL-YiYl^ . 

 Substitution in the second amido-group 

 give rise to hydracetin or pyrodin (CgH.:;- 

 NH-NH-CH,-CO) an antipyretic. 



Antithermine (antipyretic) is a con- 

 densation product of phenyl-hydrazine 

 v;ith levvilinic acid. 



-CH,— COOH 



Phenols, are a class of benzene deriva- 

 tives in which one or more H atoms are 

 replaced by hydroxyl groups (OH). 

 Those groups into which one hydroxyl 

 enters are called mono-hydric phenols, 

 the most familiar being //i^w^/ or carbolic 

 acid C«H„-OH. The next higher homo- 

 logue being cresol, 



(methyl-phenol) C,,H,<™' 



The trio-iodo derivative of this is called 

 losophan 



trio-iodo -meta-cresol C^H — OH 



^. ^l3 / 



employed in skin diseases. The next 

 homologue is thymol a propyl-cresol, 



/C.H, 

 C0H3 — CH3 = Aristol is dithymoldi- 

 ^OH iodide. 



Among the next class of benzene deriva- 

 tives in which two H atoms are replaced 

 by hydroxyl groups, the dioxy-benzenes, 

 CgH^OH). we have three isomers, the 



OH 

 Ortho. /\0H 



Pyrocatechol I 1.2 I 



methyl-acetanilid C^Hs — N<C^, 



OH 



— the Meta /\ 



Resorcinol (resorcin) | i 3 1 



\/0H 



OH 



a valuable antiseptic, 

 and the Para Hydro- 

 chinon, an antiseptic. 



I-4I 



\/ 

 OH 



The methyl ether of pyrochatechol is 

 guaiacol ^ ^ ^0CH3 the active con- 



stituent of creosote. 



-OH 



Guaiacol carbonate C6H3— OCH3 and 



V ^COOH^ 



benzoate f benzosol ^^^^qqqq h / 



are crystalline derivatives. 



