To a stirred suspension of 2.00 g of 3-amino-1-(4-fluorophenyl)-2,3-dihydro-6-methoxy-1H-indol-2-one hydrochloride, 1.33 g of sodium isoquinoline-3-carboxylate and 0.88 g of 1-hydroxybenzotriazole in 10 ml of anhydrous dimethylformamide was added 1.49 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride under ice cooling. The whole was stirred for 30 minutes. The reaction mixture was extracted by pouring a mixed solvent of ethyl acetate-tetrahydrofuran (2:1). The extract was washed with water, dried and evaporated. The residue was triturated with a mixed solvent of ethyl acetate and tetrahydrofuran to afford 2.60 g of N-[1(4-fluorophenyl)-2,3-dihydro-6-methoxy-2-oxo-1H-indol-3-yl]-3-isoquinolinecarboxamide as a powder. Melting point: 219° to 220° C.
