Sodium Hydroxide → 2-cyclopropyl-5-(3-(6-cyclopropylpyrazin-2-yl)-1H-indol-5-yl)-1,3,4-oxadiazole

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Reaction Steps

A yellow solution of 2-cyclopropyl-5-(3-(6-cyclopropylpyrazin-2-yl)-1-tosyl-1H-indol-5-yl)-1,3,4-oxadiazole (206.8 mg, 0.416 mmol) and NaOH (3.0 M, aq; 2.0 mL, 6.00 mmol) in dioxane (5.0 mL) was heated at 100° C. for 40 min. The reaction was cooled to RT and partitioned between DCM (50 mL) and H2O (30 mL). The organic layer was separated, and the aqueous layer was extracted with DCM (30 mL). The combined organic extracts were dried over sodium sulfate, filtered, and concentrated in vacuo. Chromatographic purification of the residue (silica gel, 0-100% (10% MeOH-EtOAc)/Hex) furnished 2-cyclopropyl-5-(3-(6-cyclopropylpyrazin-2-yl)-1H-indol-5-yl)-1,3,4-oxadiazole (71.0 mg, 0.207 mmol, 50%) as a yellow solid: MS (ESI, pos. ion) m/z: 344.2 (M+1). 1H NMR (400 MHz, DMSO-d6) δ ppm 12.03 (1H, br. s.), 9.06 (1H, d, J=1.4 Hz), 8.93 (1H, s), 8.41 (1H, s), 8.38 (1H, s), 7.82 (1H, dd, J=8.5, 1.7 Hz), 7.61 (1H, d, J=8.6 Hz), 2.29-2.38 (1H, m), 2.20-2.29 (1H, m), 1.13-1.25 (8H, m).

Provenance & Evidence