A mixture of 6-bromo-2-chloroquinazoline (32) (5.0 g, 20.5 mmol), 3,5-dimethoxyphenylboronic acid (33) (3.7 g, 20.5 mmol), Cs2CO3 (20.0 g, 61.5 mmol) and Pd(PPh3)2Cl2 (1.4 g, 2.1 mmol) in THF (50 mL), dioxane (50 mL) and water (10 mL) was degassed with N2 three times, and stirred at 80° C. for 3 hours. An aliquot of the reaction mixture was analyzed by both TLC and LCMS, which indicated that the reaction had proceeded to completion. The mixture was cooled to room temperature, and extracted with EtOAc (3×200 mL). The combined organic layers were washed with water and brine, dried over sodium sulfate, filtered and concentrated. The residue was purified by silica gel chromatography (petroleum ether/EtOAc=8:1) to obtain 2-chloro-6-(3,5-dimethoxyphenyl)quinazoline (34) as a light yellow solid (2.4 g, 38%). MS (ES+) C16H13ClN2O2 requires: 300. found: 301, 303 [M+H]+.
