Replacement, benzenesulfonate groups

Reductive oxidation of />-nitrotoluene to -aminobenzaldehyde, 31, 6 Reformatsky reaction, 37, 38 Reissert s compound, 38, 58 Reissert reaction, 38, 58 Replacement, benzenesulfonate groups by bromine atoms, 31, 82 bromine, by a thiol group, 30, 35 by fluorine, 36, 40 chlorine, by an amino group, 31,45 by a thiol group, 32, 101 by iodine, 30, 11 by methoxyl, 32, 79 by nitrile, 36, 50 in an imido-chloride group by an anilino group, 31, 48 chlorine and nitro by ethoxyl radicals, 32,68... 

Sulfonation Treatment of benzene with hot concentrated sulfuric acid gives benzenesulfonic acid A sulfonic acid group (—SO2OH) replaces one of the ring hydrogens... 

The reaction of benzenesulfonic acid with sodium hydroxide (first entry in Table 24.3) proceeds by the addition-elimination mechanism of nucleophilic aromatic substitution (Section 23.6). Hydroxide replaces sulfite ion (S03 ) at the carbon atom that bear s the leaving group. Thus, p-toluenesulfonic acid is converted exclusively to p-cresol by an analogous reaction ... 

Pyridinesulfonic acids exist as zwitterions e.g. 874). As for benzenesulfonic acid, the sulfonic acid group can be replaced by hydroxy or cyano groups under vigorous conditions, e.g. (874) — (873), (875). 

The replacement of the sulfonic acid group by halogen is governed largely oy groups already present on the nucleus. When there is no other group, as in benzenesulfonic acid, the replacement does not take place. The reaction occurs readily with phenolic sulfonic acids and is... 

In the first place I do not understand what is intended by the phrase the sulfoacids are substitution products. Substitution has for years been understood to mean the replacement of a number of atoms by an equivalent quantity of other atoms. I do not know in what sense benzenesulfonic acid is to be considered a substitution product of benzene, and sulfocarbolic acid of carbolic acid [phenol]. TheS group is said to enter the radical in place of hydrogen Ann, 102, 248 and 249) it substitutes. I ask what does it substitute ... 

Further, replacement of sulfo by diazo groups has been observed. It occurs extraordinarily easily on occasions when o- or />-amino- or o- or />-hydroxy-benzenesulfonic acids are coupled with diazonium salts.367... 

In the case of sulfonation of benzene, one or more hydrogen atoms are replaced by the sulfonic acid group. (-SO3H). Sulfonation of benzene with fuming sulfuric acid H2S0 + SO3) yields benzenesulfonic acid. 

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