A mixture of 1-[9-chloro-1-(2-chloro-4-methoxyphenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl]propan-1-ol (200 mg, 0.492 mmol), vinyl acetate (182 μL, 1.97 mmol), di-μ-chlorobis[(η-cycloocta-1,5-diene)iridium (I)] (16.5 mg, 0.0246 mmol) and sodium carbonate (31.3 mg, 0.295 mmol) in o-dichlorobenzene (0.98 mL) was stirred at 100° C. for 2 hr. Vinyl acetate (100 μL, 1.08 mmol) was added to the reaction mixture and the mixture was stirred at 100° C. for 1.5 hr. The reaction mixture was purified by flash column chromatography on silica gel eluting with a 10-50% ethyl acetate/n-hexane to give the title compound (175.2 mg, 0.405 mmol, 82%) as a white yellow amorphous.
