Phenol sulphonic acids

The sulphonation of phenol takes place easily on treating it with concentrated sulphuric acid. 

Phenol sulphonic acid is isomeric with the sulphuric acid ester of phenol or phenyl sulphuric acid, the difference being that already discussed as existing between sulphonic acids and sulphuric acid esters (p. 515). 

At ordinary temperatures the sulphonation of phenol yields mostly the ortho compound with some of the para. At raised temperatures the para compound only is obtained, the first formed ortho compound being converted into the para. The meta compound is not formed by direct sulphonation of phenol. As previously stated (p. 522), the alkali fusion of di-sulphonic acids yields the di-phenols. By careful fusion 

It is interesting that the para benzene di-sulphonic acid also yields the meta phenol sulphonic acid due to position rearrangement. This same rearrangement, it will be recalled, occurs in the stronger fusion of the para di-sulphonic acid, meta di-phenol being obtained (p. 522). Amino benzene sulphonic acid may also be converted into phenol sulphonic acid by diazotization and decomposition of the diazo compound with water. 

---

If phenol is heated with more concentrated nitric add (in the presence of sulphuric acid), nitration occurs ultimately at the para and at both the ortho positions, giving picric acid or 2,4,6-trinitrophenol. To prepare picric acid, however, it is more convenient first to heat the phenol with sulphuric acid, whereby a mixture of 0- and p-phenol sulphonic acids is readily obtained. If this mixture is now heated with concentrated nitric acid, nitration occurs at the... 

Supplement (combined with Volume XII) XI, 2nd 1933 1605-1739 2. Sulphonic acids Benzenesulphonic acid, 26. p-Toluenesulphonic acid, 97. Naphthalene - sulphonic acid, 155. Hydroxy-Sulphonic acids Phenol-sulphonic acid, 234. Naphthol-sulphonic... 

Homogeneous IEM are produced either by polymerization of functional monomers (e.g., polycondensation of phenol or phenol-sulphonic acid with formaldehyde) or by functionalization of a polymer film by sulphonation of a polystyrene film. 

The second stage in the preparation of picric acid is the nitration of the phenol-sulphonic acid obtained in the first stage of the process. 

Sulphonic acid-hydroxy benzenes or phenol sulphonic acids. 

In preparing picric acid the phenol is first converted into a mixture of the ortho- and para-phenol sulphonic acid (p. 626). This by the action of concentrated nitric acid and heat yields the tri-nitro phenol. The nitro phenols are all more strongly acid than phenol itself. Picric acid is a yellow crystalline solid, m.p. 122.5°, and has a distinctly bitter taste. It forms an intensely yellow solution in water and the salts are even more strongly colored. 

Manufacture (1) Chlorobenzene is nitrated with a mixture of sulphuric acid and nitric acid to produce dinitrochlorobenzene, which is synthesized to dinitro-sodium phenolate under reaction with sodium hydroxide. This is further changed to dinitrophenol with hydrochloric acid and then the dinitrophenol is nitrated by a mixture of sulphuric acid and nitric acid to trinitrophenol5 picric acid. (2) Phenol is mixed with cone, sulphuric acid and heated to obtain phenol-sulphonic acid. This is nitrated with a mixture of sulphuric acid and nitric acid to trinitrophenol. 

Also it was rationalized [65] that by reacting nitric acid on o- andp-phenol-sulphonic acid coloured quinoid intermediate additions products are transformed into nitrophenol ... 

Phenol-sulphonic acid is first prepared, vC0H4—S03H/, which is then transformed into dinitro-... 

Noyes and Clement, on the reduction of nitrobenzene in a concentrated sulphuric acid solution, obtained p-amido-phenol-sulphonic acid. Gatter-mann, starting with a similar solution, by varying the conditions of the experiment obtained directly p-amido-phenol. He explains the reaction by assuming the intermediate formation of phenyl-hydroxyl-amine, which on further reduction changes by molecular rearrangement into the final product. By similar treatment were formed ... 

ABSTHACI. The nev clathrates based on di- and triethylene glycol ether of phenol sulphonic acid-4 ana 1-naphtol-sulphonic acid-4 are piesented.The four series of p-substitutea phenol esters were obtained /Pig,1/, Generally, only the derivatives of triethylene glycol ether of naphtolsulphonic acid give complexes with benzene or toluene /Tab.I/, but not with... 

Appearance liquid Phenol sulphonic acid Concentration % 65... 

Appearance liquids/powders Phenol sulphonic acid condensates Concentration % Various... 

Diphenols, phenolcarboxylic acids and phenol sulphonic acids are in Table 8.6. Aminophenols and the hydroxy-derivatives of heterocyclic bases are in Table 8.11. 

---