Ethanol → HCID 69872870, compound

Participants

Reaction Steps

A solution of 2-(4-{2-[2-(4-bromophenyl)-5-methyloxazol-4-yl]ethoxy}phenoxy)-2-methyl-propionic acid ethyl ester (907 mmol) (see Ex. 2, part B) and 1-(t-butoxycarbonyl)pyrrole-2-boronic acid (0.998 mmol) in toluene:ethanol (18.2 mL of a 1:1 solution) was treated with Na2CO3 (aq) (0.906 mL of a 2M solution). A nitrogen atmosphere was applied, Pd(PPh3)4 (52.5 mg) was added, and the orange mixture was heated at reflux for 2 h. After cooling to room temperature, the mixture was partitioned between ethyl acetate (20 mL) and H2O (30 mL). The layers were separated, and the aqueous phase was back-extracted with ethyl acetate (2×10 mL). Combined organic phases were washed with brine (20 mL), dried over Na2SO4, and concentrated. The product was purified by silica gel chromatography (20 g SiO2, 3:7 ethyl acetate:hexanes) to yield the product in 92% yield as an oil; Rf=0.50 in 1:4 ethyl acetate:hexanes; 1H NMR (400 MHz, CDCl3) δ7.92 (d, J=8.0 Hz, 2H), 7.37 (d, J=8.0 Hz, 2H), 7.34 (t, J=2.4 Hz, 1H), 6.79 (d, J=9.4 Hz, 2H), 6.74 (d, J=9.4 Hz, 2H), 6.21 (d, J=2.4 Hz, 2H), 4.20 (q, J=6.8 Hz, 2H), 4.16 (t, J=6.8 Hz, 2H), 2.93 (d, J=6.8 Hz, 2H), 2.34 (s, 3H), 1.49 (s, 6H), 1.33 (s, 9H), MS (EI) 598.2 (M+Na)+, 575.2 (M+H)+.

Provenance & Evidence