Chlorosulfonic acid → (E)-ethyl 3-(4-(4-(chlorosulfonyl)phenoxy)-3,5-difluorophenyl)-2-methylacrylate

Participants

Reaction Steps

To a solution of (E)-ethyl 3-(3,5-difluoro-4-phenoxyphenyl)-2-methylacrylate (intermediate 41.2) (1 g, 3.14 mmol) in DCM (3.14 mL) under N2 was added chlorosulfonic acid (0.419 mL, 6.28 mmol) dropwise. After 1 hour an additional 0.209 mL chlorosulfonic acid was added. After an additional hour the reaction mixture was quenched with ice-water and extracted into EtOAc (2×200 mL). The combined organic layers were dried briefly (<10 min) over Na2SO4 and concentrated to recover 1.283 g of the title compound (98%) as a yellow oil.

Provenance & Evidence