Dimethylformamide → 3-(3-{(5-Fluoro-8-methoxychroman-6-yl)-[4-(5-methyl-[1,2,4]oxadiazol-3-yl)phenylamino]methyl}-5-oxo-4,5-dihydro-[1,2,4]triazol-1-yl)thiophene-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To 1 ml of a DMF solution containing 100 mg of [2-(5-fluoro-8-methoxychroman-6-yl)-2-[4-(5-methyl-[1,2,4]oxadiazol-3-yl)phenylimino]-1-methylsulfanylethylidene]carbamic acid methyl ester (Example (33d)), 35 mg of 3-hydrazinothiophene-2-carboxylic acid methyl ester and 0.028 ml of triethylamine were added. The resulting mixture was stirred at 85° C. for 12 hours under a nitrogen atmosphere and then concentrated. The residue was dissolved in 1.5 ml of methanol, 1.5 ml of THF, and 0.1 ml of acetic acid, and 100 mg of sodium cyanotrihydroborate was further added thereto. The mixture was stirred at room temperature for 3 hours, and 1 ml of a 5 N sodium hydroxide aqueous solution was added thereto. The mixture was stirred at room temperature overnight. Acetic acid (0.3 ml) was added to the reaction mixture, and the resulting mixture was crudely purified by reverse-phase high performance liquid chromatography (acetonitrile-water, 0.1% acetic acid) to give a crude product of 3-(3-{(5-fluoro-8-methoxychroman-6-yl)-[4-(5-methyl-[1,2,4]oxadiazol-3-yl)phenylamino]methyl}-5-oxo-4,5-dihydro-[1,2,4]triazol-1-yl)thiophene-2-carboxylic acid.

Provenance & Evidence