Potassium Phosphate, Tribasic → 2-cyclopropyl-5-(3-(6-cyclopropylpyrazin-2-yl)-1-tosyl-1H-indol-5-yl)-1,3,4-oxadiazole

Participants

Reaction Conditions

Reaction Steps

A brown mixture of 2-cyclopropyl-5-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1-tosyl-1H-indol-5-yl)-1,3,4-oxadiazole (298.4 mg, 0.590 mmol), 2-bromo-6-cyclopropylpyrazine (CombiPhos Catalysts, Inc., Princeton, N.J.; 129 mg, 0.649 mmol), Pd2(dba)3 (16.22 mg, 0.018 mmol), dicyclohexyl(2′,4′,6′-triisopropylbiphenyl-2-yl)phosphine (XPhos; 16.89 mg, 0.035 mmol), and potassium phosphate (376 mg, 1.771 mmol) in a mixture of dioxane (5.0 mL) and water (0.500 mL) was sparged with argon then heated at 100° C. for 2 h. The reaction was then cooled to RT, diluted with DCM (20 mL), and concentrated onto silica gel. Chromatographic purification (silica gel, 0-100% EtOAc/Hex) furnished 2-cyclopropyl-5-(3-(6-cyclopropylpyrazin-2-yl)-1-tosyl-1H-indol-5-yl)-1,3,4-oxadiazole (230 mg, 0.462 mmol, 78%) as a light-yellow solid: MS (ESI, pos. ion) m/z: 498.6 (M+1). 1H NMR (400 MHz, CDCl3) δ ppm 8.99 (1H, s), 8.75 (1H, s), 8.43 (1H, s), 8.18 (1H, s), 8.12 (2H, s), 7.84 (2H, d, J=8.4 Hz), 7.28 (2H, s), 2.36 (3H, s), 2.24-2.32 (1H, m), 2.12-2.21 (1H, m), 1.25-1.31 (4H, m), 1.15-1.23 (4H, m).

Provenance & Evidence