3-Chloro-2-fluorophenylboronic Acid → HCID 71255708, compound

Participants

Reaction Steps

Ethyl 1-(3-chloro-2-fluorophenyl)-5-methyl-1H-imidazole-4-carboxylate: Using a modified procedure of Sreedhar. (Reference: Sreedhar, B., Synthesis, 795 (2008)). To a suspension of ethyl 4-methyl-1H-imidazole-5-carboxylate (0.530 g, 3.44 mmol) and (3-chloro-2-fluorophenyl)boronic acid (0.500 g, 2.87 mmol) in MeOH (5.74 mL) was added cuprous oxide (0.041 g, 0.287 mmol). The resulting purple suspension was stirred vigorously under an atmosphere of air (drying tube used). After 20 h, the reaction mixture was filtered to remove the solids and the clear blue filtrate was concentrated to give a blue solid. The blue solid was suspended in DCM and filtered to remove the solids and the blue filtrate was concentrated to give a pale blue solid weighing 0.187 g. Purification by normal phase chromatography gave ethyl 1-(3-chloro-2-fluorophenyl)-4-methyl-1H-imidazole-5-carboxylate (0.0187 g, 2%) as a clear, colorless residue and ethyl 1-(3-chloro-2-fluorophenyl)-5-methyl-1H-imidazole-4-carboxylate (Intermediate 24A) (0.0079 g, 1%) as a clear, colorless residue. MS(ESI) m/z: 283.1 (M+H)+.

Provenance & Evidence