Ethanol → HCID 69871472, 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 3,5-dimethylisoxazole-4-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=0.16 in 1:4 ethyl acetate:hexanes; 1H NMR (400 MHz, CDCl3) δ7.99 (d, J=8.4 Hz, 2H), 7.27 (d, J=8.4 Hz, 2H), 6.78 (d, J=8.8 Hz, 2H), 6.73 (d, J=8.8 Hz, 2H), 7.06-7.01 (m, 2H), 4.18 (q, J=7.2 Hz, 2H), 4.15 (t, J=6.4 Hz, 2H), 2.92 (t, J=6.4 Hz, 2H), 2.39 (s, 3H), 2.33 (s, 3H), 2.25 (s, 3H), 1.48 (s, 6H), 1.23 (t, J=7.2 Hz, 3H); MS (EI) 528.2 (M+Na)+, 505.2 (M+H)+.

Provenance & Evidence