BENZENE SERIES. AROMATIC COMPOUNDS. 

 NO, OH 



561 



H C 



\ c x 





II 



H 



H 



Nitro-benzene, C 6 H 6 NO a . 



CH 



Toluene, methyl-benzene. 

 C 6 H 6 .CH 3 . 



CH 3 



H 



H 



Xylene, di-methyl-benzene, 



CH, 



H 



C0 2 H 



XC0 2 H 



A 



H 



Resorcin, C e H 4 (OH) 2 . Phthulic acid, C H 4 (CO 2 H) a . 



H 



OH 



L 



J 



OH 



\ OH 



H 



OH 



I 



C0 2 ] 



Pyrogallol, C 6 H 3 (OH) 3 . Galb'c acid, C 6 H 2 .CO 2 H.(OH),. 



OH 

 H \A 



OH 



H 



/ 



X CH 3 

 \H 



H 



H 



/ 



H 



Cresol, C 6 H 4 .CH 3 .OH. 



CH 



Salicylic acid, C 6 H 4 .CO 2 H.OH. 

 COH 



\ 



\^f 



i 3 H 7 



H 



Cymene, methyl-propyl benzene. Thymol, C 6 H 3 CH 3 .C 8 H 7 .OH. Benzaldehyde, oil of bitter 

 C 6 H 4 CH 3 .C 3 H 7 . almond, C 6 H 6 .COH. 



The preceding graphic formulas show in the first column (besides 

 nitro-benzene) a number of hydrocarbons, in the second column 

 phenols, obtained by introducing hydroxyl into the hydrocarbon 

 molecule, and in the third column chiefly aromatic acids, formed by 

 introducing carboxyl, CO 2 H, or carboxyl and hydroxyl. 



Differences between aromatic and fatty compounds. Substitution pro- 

 ducts with nitric acid, sulphuric acid, bromine, hydrocarbon radicals, etc., are 

 much more easily formed and held much more strongly in aromatic compounds 

 than in fatty ones. The phenols, which in composition correspond to alcohols, 

 36 



