Pyridine → 1-(5-chloro-2-methoxy-benzenesulfonyl)-2,3-dihydro-1H-indole-6-carboxylic acid [4-(5-oxo-4,5-dihydro-[1,2,4]oxadiazol-3-yl)-phenyl]-amide

Participants

Reaction Conditions

Reaction Steps

A solution of 1-(5-chloro-2-methoxy-benzenesulfonyl)-2,3-dihydro-1H-indole-6-carboxylic acid [4-(N-hydroxycarbamimidoyl)-phenyl]-amide (254 mg, 0.51 mmol) in dimethylformamide (3.5 ml) was treated with pyridine (0.04 ml, 1 equiv.) and the mixture was cooled to 0° C. Chloroformic acid 2-ethylhexyl ester (98 mg, 0.51 mmol, 1 equiv.) was added dropwise. The reaction mixture was stirred at 0° C. for 30 min, then quenched with water. The slurry was extracted three times with ethyl acetate. The combined organic layers were dried with Na2SO4 and the solvent was evaporated. The crude compound was suspended in xylene and heated at reflux for 2 hours. After cooling to room temperature, the solid was filtered and dried under high vacuum, yielding 1-(5-chloro-2-methoxy-benzenesulfonyl)-2,3-dihydro-1H-indole-6-carboxylic acid [4-(5-oxo-4,5-dihydro-[1,2,4]oxadiazol-3-yl)-phenyl]-amide as a white solid, 114 mg (43%). MS (ISP): m/e=525.2 (M−H), δH (300 MHz; d6-DMSO) 10.31 (1H, s), 7.55-7.80 (8H, m), 7.28 (1H, d), 7.16 (1H, d), 4.04 (2H, t), 3.60 (3H, s), 3.06 (2H, t).

Provenance & Evidence