Practical method for the large-scale synthesis of 4′-chloro-2-nitrobiphenyl: A key intermediate of Boscalid

Boscalid is a pesticide with the advantages of broad spectrum bactericidal activity, high efficiency, low toxicity, and no cross-resistance with other fungicides currently available on the market. Herein, we report the synthesis of 4′-chloro-2-nitrobiphenyl, a key intermediate of Boscalid using a palladium-catalyzed Suzuki-Miyaura cross-coupling employing the 2-aryl-substituted indenyl phosphine ligand. 4′-Chloro-2-nitrobiphenyl was prepared in 94 % yield on a 100 g scale. This method allows for the industrial production of alimide and active substances bearing a biphenyl moiety.