A mixture of 5-(2-hydroxy-2-pyridin-3-ylvinyl)-7-methoxy-2,3-dihydroimidazo[1,2-c]quinazolin-8-ol hydrochloride (Example 1-4) 50.4 mg (0.14 mmol), methyl chlorobutyrate 22.2 mg (0.16 mmol) and potassium carbonate 186.9 mg (1.35 mmol) in N,N-dimethylformamide 1 mL was stirred at 120° C. for 4 hours. The reaction mixture was poured into water and extracted into dichloromethane. The organic layer was washed with brine, dried over MgSO4, filtrated and the solvent was evaporated. The residue was washed by diethyl ether to give the title compound 35.0 mg as yellow solid. Yield 59.3%.
