Triethylamine → Methyl 2-(6-cyano-5-(2,4-dichlorophenyl)-7-methylimidazo[1,2-a]pyrimidin-2-yl)acetate

Participants

Reaction Steps

To a suspension of methyl 2-(6-carbamoyl-5-(2,4-dichlorophenyl)-7-methylimidazo[1,2-a]pyrimidin-2-yl)acetate (766 mg, 1.95 mmol) in CH2Cl2 (20 mL) was added Et3N (592 mg, 5.85 mmol) and trifluoroacetic anhydride (819 mg, 3.90 mmol). The reaction mixture became a dark brown-green solution within 2 min. Satd aq NH4Cl (20 mL) was added after 30 min. The organic layer was washed with 20 mL each of satd aq NaHCO3 and water, followed by drying with MgSO4, filtration, and concentration under reduced pressure. The residue was purified by silica gel chromatography eluting product through a 40 mm i.d. by 150 mm column with 1.5% MeOH in CH2Cl2. Concentration of the fractions containing product gave methyl 2-(6-cyano-5-(2,4-dichlorophenyl)-7-methylimidazo[1,2-a]pyrimidin-2-yl)acetate (583 mg, 80%) as a yellow foam.

Provenance & Evidence