C. Graebe (Ann., 1869, 149, p. 22) orientated the ortho-compound or phthalic acid from its formation from naphthalene on oxidation; the meta-compound or isophthalic acid is orientated by its production from mesitylene, shown by A.
2 3, p. 2 377) investigated the condensation of pyroracemic acid, CH 3 CO 000H, with various aliphatic aldehydes, and obtained from two molecules of the acid and one of the aldehyde in the presence of baryta water alkylic isophthalic acids: with acetaldehyde [1.3.51-methylisophthalic acid or uvitic acid, C 6 H 3 CH 3 (000H) 2, was obtained, with propionic aldehyde [1.3.
Abietic acid can be extracted from colophony by means of hot alcohol; it crystallizes in leaflets, and on oxidation yields trimellitic, isophthalic and terebic acid.
Soc., 1891, 59, p. 79 8); by the action of trimethylene bromide on disodio-propane tetracarboxylic ester; and by the reduction of isophthalic acid with sodium amalgam, the tetrahydro acids first formed being converted into hydrobromides and further reduced (A.
There are three isomers: (1) ortho, or phthalic acid; (2) meta, or isophthalic acid; (3) para, or terephthalic acid.