Triethylamine → 5-Chloro-1-[5-chloro-2-(dimethylsulfamoyl)benzyl]-2-imino-1,2-dihydropyridine-3-carboxamide hydrochloride

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Reaction Conditions

Reaction Steps

(Step 3) To a suspension of 2-cyano-2-(3,4-dichloro-5-oxo-2,5-dihydrofuran-2-yl)acetamide (0.50 g) in methanol (10 ml) was added a solution of 2-(aminomethyl)-4-chloro-N,N-dimethylbenzenesulfonamide hydrochloride obtained in Step 2 (0.85 g) and triethylamine (0.58 ml) in methanol (5 ml) at room temperature, and the mixture was stirred overnight at 50° C. The reaction solvent was evaporated under reduced pressure, acetic acid (5 ml) was added, and the mixture was stirred at 50° C. for 2 hr. The solvent was evaporated under reduced pressure, the residue was extracted with 1N hydrochloric acid, and the extract was washed with ethyl acetate. The aqueous layer was basified with 1N aqueous sodium hydroxide solution, and the mixture was extracted with ethyl acetate. The organic layer was dried over sodium sulfate. The solvent was evaporated under reduced pressure. The residue was purified by basic silica gel column chromatography (ethyl acetate:hexane=7:3→1:0). The obtained residue was dissolved in methanol, and 4N hydrogen chloride-ethyl acetate solution (1 ml) was added. The mixture was crystallized from methanol-ethyl acetate. The precipitated crystals were collected by filtration, and recrystallized from methanol-ethyl acetate to give the title compound (0.43 g).

Provenance & Evidence