7-(5-{3-chloro-4-[(1-methylethyl)oxy]phenyl}-1,2,4-oxadiazol-3-yl)-1H-indole (D51) (708 mg), DABCO (112 mg), and N,N-Dimethylformamide (4 mL) were added to dimethyl carbonate (10 mL) at room temperature under stirring. The reaction mixture was heated to 130° C. for 36 h. After cooling the reaction, the organic solvent was evaporated off. The residue was purified by column chromatography (25% EtOAc in hexane) to afford 7-(5-{3-chloro-4-[(1-methylethyl)oxy]phenyl}-1,2,4-oxadiazol-3-yl)-1-methyl-1H-indole (D58) (486 mg) as a pale yellow solid. δH (CDCl3, 400 MHz): 1.46 (6H, d), 3.78 (3H, s), 4.71-4.76 (1H, m), 6.60 (1H, d), 7.08 (1H, dd), 7.21 (1H, t), 7.56 (1H, dd), 7.80 (1H, dd), 7.96 (1H, dd), 8.27 (1H, d). MS (ES): C20H15ClN3O2 requires 367; found 368.1 (M+H+).
