From this substance, an oxybenzoic acid (meta-), C 6 H 4.
OH COOH, may be prepared; and the two other known oxybenzoic acids (ortho- and para-) may be converted into benzoic acid.
These three acids yield on heating phenol, identical with the substance started with, and since in the three oxybenzoic acids the hydroxyl groups must occupy positions other than I, it follows that four hydrogen atoms are equal in value.
This substance readily yields ortho-oxybenzoic acid or salicylic acid, which on nitration yields two mononitro-oxybenzoic acids.
Thus potassium ortho-oxybenzoate is converted into the salt of para-oxybenzoic acid at 220 0; the three bromphenols, and also the brombenzenesulphonic acids, yield m-dioxybenzene or resorcin when fused with potash.
Potassium chlorate and hydrochloric acid oxidize phenol, salicylic acid (o-oxybenzoic acid), and gallic acid ([2.3.4] trioxybenzoic acid) to tri chlorpyroracemic acid (isotrichlorglyceric acid), CC13 C(OH)2 C02H, a substance also obtained from trichloracetonitrile, CC1 3 CO CN, by hydrolysis.
'Cooh Ci, BrC CO CBr3+ H H2 HC ("CH, HC C /CH, H02C C02HCI CI (t) (2) C(3) (4) (5) The reduction of o-oxybenzoic acids by sodium in amyl alcohol solution has been studied by A.
On fusion with alkalis it yields para-oxybenzoic acid, and nas cent hydrogen reduces it to hydro shikimic acid.
It is to be noted in the Kolbe method of synthesis that potassium phenolate may be used in place of the sodium salt, provided that the temperature be kept low (about 150° C.), for at the higher temperature (220° C.) the isomeric para-oxybenzoic acid is produced.