Chlor toluenes

These chlorine substitution products of toluene are known as chlor-toluenes because all of them still have the toluene character, i.e. a benzene ring in which one hydrogen is substituted by methyl. 

Isomerism.— As all of the second group, in which substitution occurs in the side chain, considered as benzene derivatives, are mono-substituted benzenes, they do not exist in isomeric forms, and only one compound of each formula is known. The first group, however, in which halogen substitution occurs in the ring, are all poly-substitution products of benzene, since toluene itself is a mono-substituted benzene. Mono-chlor toluene is, therefore, a di-substituted benzene, and occurs in the three forms, as follows ... 

By the ordinary chlorination of toluene in presence of a carrier the ortho (1-2) and para (1-4) products are formed. Di-chlor toluene, in the... 

The mono-nitro toluenes, like the mono-chlor toluenes being di-substituted benzenes, are known in the three isomeric forms. 

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