Patent ID: 7351856

Claim:
A process for preparing a hydroxy aromatic acid that is described by the structure of Formula I (COOH) m —Ar—(OH) n I wherein Ar is a C 6 -C 20 arylene radical, n and m are each independently a nonzero value, and n+m is less than or equal to 8, comprising the steps of (a) contacting a halogenated aromatic acid that is described by the structure of Formula II, (COOH) m —Ar—(X) n II wherein each X is independently Cl, Br or I, and Ar, n and m are as set forth above, with a base in water to form therefrom the corresponding m-basic salt of the halogenated aromatic acid in water; (b) contacting the m-basic salt of the halogenated aromatic acid with a base in water, and with a copper source in the presence of a ligand that coordinates to copper, to form the m-basic salt of a hydroxy aromatic acid from the m-basic salt of the halogenated aromatic acid at a solution pH of at least about 8, wherein the ligand comprises a diketone described by Formula IV wherein A is R 1 and R 2 are each independently selected from substituted and unsubstituted C 1 -C 16 n-alkyl, iso-alkyl and tertiary alkyl groups; and substituted and unsubstituted C 6 -C 30 aryl and heteroaryl groups; R 3 is selected from H; substituted and unsubstituted C 1 -C 16 n-alkyl, iso-alkyl and tertiary alkyl groups; substituted and unsubstituted C 6 -C 30 aryl and heteroaryl groups; and a halogen; R 4 , R 5 , R 6 and R 7 are each independently H or a substituted or unsubstituted C 1 -C 16 n-alkyl, iso-alkyl or tertiary alkyl group; and n=0 or 1; (c) optionally, separating the m-basic salt of the hydroxy aromatic acid from the reaction mixture in which it is formed; and (d) contacting the m-basic salt of the hydroxy aromatic acid with acid to form therefrom an n-hydroxy aromatic acid.