Oxygen → 2,5-Cyclohexadiene-1,4-dione, 2,3,5-trimethyl-

Participants

Reaction Steps

In the process for the preparation of 2,3,5-trimethylhydroquinone by (a) catalytic oxidation of a trimethylphenol starting material selected from the class consisting of 2,3,5-trimethylphenol, 2,3,6-trimethylphenol and mixtures thereof by reaction with oxygen in the presence of a cobalt chelate complex in a dimethylformamide solvent to afford 2,3,5-trimethyl-p-benzoquinone followed by (b) catalytic hydrogenation of the 2,3,5-trimethyl-p-benzoquinone thus formed by reaction with hydrogen in the presence of a noble metal catalyst, the improvement which comprises; (1) mixing the 2,3,5-trimethyl-p-benzoquinone containing reaction mixture from step (a) with di-n-butyl ether and water to form a di-n-butyl ether phase containing 2,3,5-trimethyl-p-benzoquinone, a precipitate comprising the cobalt catalyst and an aqueous phase containing the dimethylformamide reaction solvent, (2) separating the di-n-butyl ether phase from the precipitate and aqueous phase, and (3) subjecting the separated di-n-butyl ether phase to catalytic hydrogenation according to reaction step (b), said di-n-butyl ether functioning as the reaction solvent.

Provenance & Evidence