Synthesis of Vicinal 2,3-Dialkyl-6-hydroxybenzophenones by Titanium Tetrachloride Catalyzed Fries Rearrangement of 3,4-Dialkylphenyl Benzoates

The titanium(IV) chloride-mediated Fries rearrangement of 3,4-dialkylphenyl benzoates 1 yields mainly 4,5-dialkyl-2-hydroxy-benzophenones 2 in high yield. We describe here a new access to the unknown vicinal 2,3-dialkyl-6-hydroxybenzophenones 3, which is based on the protection of the most reactive position of 1 by bromination