A small screw cap test tube was charged with 5-Acetyl-thiophene-2-carboxylic acid [3-(3-hydroxymethylene-2-oxo-2,3-dihydro-1H-indole-6-carbonyl)-phenyl]-amide (prepared below, 100 mg, 0.231 mmol) and THF (2 mL). To the resulting solution was added 5-amino-2-methoxyphenol (35.39 mg, 0.254 mmol), and the mixture was stirred for 24 h at 65° C. Subsequently, the reaction mixture was cooled to room temperature. Hexanes were added to the reaction mixture. The solid precipitate that formed was washed with ˜1 mL of i-prOH yielding 59% (75 mg, 0.136 mmol) of the title compound.
