4-Cyanobenzaldehyde → 2-bromo-5-[(4-cyano-phenyl)-hydroxy-methyl]-1-isopropyl-1H-imidazole-4-carboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

LDA (2 M in THF, 53.6 mL, 107 mmol) was added slowly (over 30 min) to a cold (−78° C.) solution of intermediate A (20 g, 77 mmol) in THF (400 mL) (during the addition, the temperature raised to −70° C.). The mixture was stirred for 1 h at −78° C. A solution of 4-cyanobenzaldehyde (14 g, 107 mmol) in THF (100 mL) was added slowly. The reaction mixture was stirred for 30 min at −78° C., allowed to warm to −20° C. over 1 h, quenched by addition of acetic acid (10 mL), diluted with EtOAc/water, and extracted with EtOAc. The organic extracts were washed with water and brine, dried (Na2SO4), filtered, and concentrated. The residue was purified by flash chromatography (hexane/EtOAc, 1:1), followed by trituration in EtOAc, to provide 20.1 g of the title compound. tR: 0.99 min (LC-MS 2); ESI-MS: 392.2/394.1 [M+H]+ (LC-MS 2); Rf=0.29 (hexane/EtOAc, 1:1).

Provenance & Evidence