Phosphorus oxychloride → 2-cyclopropyl-5-(3-iodo-1-tosyl-1H-indol-5-yl)-1,3,4-oxadiazole

Participants

Reaction Conditions

Reaction Steps

In a 50 mL RBF, N′-(cyclopropanecarbonyl)-3-iodo-1-tosyl-1H-indole-5-carbohydrazide (1.13 g, 2.159 mmol) was treated with POCl3 (5 mL, 53.6 mmol), under argon. The flask was fitted with a reflux condenser. The reaction was stirred and heated at 110° C. for 1.25 h. The crude material was treated with water and extracted with EtOAc. The organic layer was washed with brine, dried, filtered and concentrated to 20 mL of solvent. When about 20 mL of solvent remained, a brown solid precipitated and was collected by filtration. The mother liquor was purified with flash chromatography to give 2-cyclopropyl-5-(3-iodo-1-tosyl-1H-indol-5-yl)-1,3,4-oxadiazole (570 mg, 1.128 mmol, 52.2). MS (ESI, pos. ion) m/z: 506.0 (M+1). 1H NMR (400 MHz, DMSO-d6) δ ppm 8.23 (s, 1H), 8.15 (d, J=8.6 Hz, 1H), 7.94-8.03 (m, 3H), 7.85 (s, 1H), 7.43 (d, J=8.0 Hz, 2H), 2.28-2.37 (m, 4H), 1.09-1.21 (m, 4H).

Provenance & Evidence