To a solution of 8-bromo-2-chloroquinazolin-4(3H)-one (407c; 0.110 g, 0.424 mmol) in 2 mL DME and 0.5 mL DMF in an ice/water bath was added sodium hydride (60% in mineral oil; Aldrich; 0.019 g, 0.466 mmol). After 10 min, lithium bromide (Aldrich; 0.074 g, 0.848 mmol) was added and the reaction was warmed to RT. After 15 min, (3-bromopropoxy)-tert-butyldimethylsilane (0.108 mL, 0.466 mmol) was added. After 30 min, the reaction was placed in a 60° C. oil bath and heated over the weekend. The reaction was partitioned between water and EtOAc. The aq layer was extracted 2× EtOAc and The combined organic layers were washed with water 2 times, satd aq NaCl once, and the organics were dried over anhydrous Na2SO4, filtered, and concentrated in vacuo. The material was treated with DCM and purified by silica gel chromatography using 0-20% EtOAc/hexane. The product-containing fractions were concentrated to afford 8-bromo-3-(3-((tert-butyldimethylsilyl)oxy)propyl)-2-chloroquinazolin-4(3H)-one (0.080 g, 0.185 mmol, 43% yield) as a yellow oil. 1H NMR (400 MHz, CDCl3) δ ppm 8.21 (1H, dd, J=7.9, 1.3 Hz), 8.02 (1H, dd, J=7.8, 1.4 Hz), 7.34 (1H, t, J=7.8 Hz), 4.38-4.50 (2H, m), 3.78 (2H, t, J=5.8 Hz), 1.96-2.05 (2H, m), 0.89 (9H, s), 0.03-0.08 (6H, m). m/z (ESI, +ve ion) 431.0/433.0/435.0 (M+H)+.
