Potassium Cyanide → Methyl 4-bromo-2-cyanobenzoate

Participants

Reaction Conditions

Reaction Steps

A suspension of methyl 2-amino-4-bromobenzoate (500 mg, 2.2 mmol) in 2 mL of conc. HCl was added 5 mL of water and a solution of NaNO2 (159 mg, 2.3 mmol) in water (1 mL) was added over a 10-minute period at 0° C. This diazonium solution was then brought to pH 6 with aqueous NaHCO3. In a separated vail, a solution of CuSO4 (660 mg, 2.75 mmol) in water (2 mL) was added dropwise to a solution of KCN (657 mg, 10.11 mmol) in water (2 mL) at 0° C., then toluene (5 mL) was added and the mixture was stirred and heated to 60° C. The previously prepared diazonium solution was added dropwise to the brown CuCN solution at 60° C. over 40 min. The reaction mixture was heated to 70° C. for 1 hour and cooled to room temperature, and EtOAc (100 mL) was added. The organic phase was washed with brine (20 mL) and concentrated. The crude product was purified via cprep-TLC to afford the methyl 4-bromo-2-cyanobenzoate. 1H-NMR (400 MHz, CDCl3) δ 7.75-7.95 (m, 3H), 3.93 (s, 3H).

Provenance & Evidence