Fries rearrangement: scalable synthesis of key fluoro building blocks 3-fluoro-4-methoxybenzoyl chloride and 1,2-diethoxy-3-fluorobenzene

Abstract Lewis acid catalyzed Fries rearrangement of 2-fluorophenyl acetate ( 3 ) was performed on kg scale. The ortho 5 and para 4 isomers obtained were separated in an industrially feasible way. Compound 4 was then converted into fluorinated building block 3-fluoro-4-methoxybenzoyl chloride ( 1 ) while compound 5 was converted into 1,2-diethoxy-3-fluorobenzene ( 2 ) in high yields.