(2,4-Dichlorophenyl)boronic acid → 8-(2,4-Dichlorophenyl)-2-ethylimidazo[1,2-a]pyrazine-3-carboxylic acid methyl ester

Participants

Reaction Steps

8-Chloro-2-ethylimidazo[1,2-a]pyrazine-3-carboxylic methyl ester (0.92 g, 3.8 mmol) synthesized in Reference Example 1 was dissolved in a mixed solvent of toluene (32 mL) and methanol (8 mL), then 2,4-dichlorobenzeneboronic acid (1.49 g, 7.8 mmol) and tetrakistriphenylphosphine palladium complex (230 mg, 0.2 mmol) were added thereto, and the mixture was heated under reflux for 2 hours under nitrogen atmosphere. The reaction mixture was allowed to cool, and purified by silica gel column chromatography (n-hexane:ethyl acetate=3:1) to give the title compound (1.03 g) as a pale yellow crystals.

Provenance & Evidence