Mono chlor benzene

Mono-chlor-benzene Di-brom-benzene Hydroxy benzene Amino benzene Methyl benzene... 

Mono-chlor benzene, CeHaCl.. Penta-chlor benzene, CeHCU.. 

Benzyl chloride Mono-chlor-methyl benzene... 

Because, as we shall see later, the mono-chlor-methyl benzene yields benzyl alcohol it is known as benzyl chloride. The di-chlor-methyl benzene similarly yields benzaldehyde, and is, therefore, called benzal chloride, and the third is also called benzo tri-chloride. 

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 ... 

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

The direct chlorination or bromination of aniline takes place more easily than that of benzene, the result being the symmetrical tri-chlor or tri-brom aniline, viz., i-amino 2-4-6-tri-chlor benzene, C6H2CI3-(NH2) and I-amino 2-4-6-tri-brom benzene, CeH2Br3(NH2). The mono-halogen anilines are prepared by reducing mono-chlor nitro benzenes, or by halogenating acetanilide and then hydrolyzing. 

With the simple aryl halides such as the mono-chlor derivatives of benzene or its homologues this reaction does not take place. Tf, however, a benzene halide has also substituted in the ring two nitro, sul-phonic acid or carboxyl groups, in the ortho and para positions to the halogen, then treatment of the halide with potassium hydroxide results in replacing the halogen with hydroxyl and the corresponding substituted phenol will be obtained. 

Chlor Naphthalenes.—Another series of reactions which support the view just discussed, that in naphthalene there are present two nuclei either one of which is a benzene ring, is found in Laurent s work on the chlorine substitution products of naphthalene. When naphthalene is chlorinated it yields different chlor naphthalenes. Two of these are important in this place, viz., a tetra-chlor naphthalene, C10H4CI4 and a penta-chlor naphthalene, C10H3CI5. Now the first one must have all four chlorines linked to one nucleus because on oxidation it yields ortho-phthalic acid, as below. The penta-chlor compound must of necessity have at least one of the chlorines linked to the second nucleus as only four are possible of being linked to one nucleus. Now this compound on oxidation yields not mono-chlor phthalic acid but tetra-chlor phthalic acid. The reactions may be represented as follows ... 

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