Revisiting the synthesis of bis(2‐hydroxy‐3,5‐di‐t‐butylphenyl)methanone

Described is our effort toward establishing a practical and sustainable synthesis of bis(2‐hydroxy‐3,5‐di‐t‐butylphenyl)methanone. In it, we found the phenol‐aldehyde condensation could be efficiently catalyzed by sulfonic acid‐functionalized microporous carbon spheres (MCS‐SO3H). Additionally, we developed practical and sustainable procedures for the synthesis of the title ligand by applying readily available reagents in lieu of toxic chromium trioxide and fuming boron tribromide.