Trifluoroacetic acid → 5-(3-Chloro-4-methoxyphenyl)-3-(indolin-5-yl)-1,2,4-oxadiazole

Participants

Reaction Steps

To a solution of the product of Step E (0.11 g; 0.34 mmol) in 1M BH3 in THF (0.68 ml; 0.68 mmol) CF3CO2H (1 ml) was added drop wise at 0° C. with stirring. After the addition was completed (˜5 min) the reaction was quenched with H2O (0.5 ml) and the solvents were removed under reduced pressure. The residue was diluted to 15 ml with EtOAc and was washed with 1 M NaOH (2×2 ml), brine and dried over anhydrous MgSO4 and filtered. The filtrate was evaporated to dryness under reduced pressure to give the title compound (0.11 g; 100%) as a creamy foam, which was used in the next step without further purification. 1H-NMR (CDCl3) 2.6 (broad s, 1H+H2O); 3.12 (tr, 2H, J=8.4 Hz); 3.66 (tr, 2H, J=8.4 Hz); 3.98 (s, 3H); 6.71 (d, 1H, J=8.1 Hz); 7.07 (d, 1H, J=8.7 Hz); 7.83-7.88 (m, 2H); 8.05 (dd, 1H, J=2, 8.7 Hz); 8.21 (d, 1H, J=2 Hz).

Provenance & Evidence