Patent ID: 8524923

Claim:
A process for the preparation of a diacid of the formula HOOC—R′—COOH from an alcohol/aldehyde of the formula HOH 2 C—R′—(C═O)H, wherein R′ is an optionally substituted furan ring, comprising the steps: (a) contacting the alcohol/aldehyde with an oxidant in the presence of a metal bromide catalyst forming a dialdehyde having the formula H(C═O)—R′—(C═O)H, and optionally isolating the dialdehyde; (b) contacting the dialdehyde with an oxidant in the presence of a metal bromide catalyst forming an acid/aldehyde having the formula HOOC—R′—(C═O)H, and optionally isolating the acid/aldehyde; and (c) contacting the acid/dialdehyde with an oxidant in the presence of a metal bromide catalyst forming the diacid, and optionally isolating the diacid.