反应详情

By the method of Example 2, 2-thiopheneacetic acid is reacted with 5,6-diamino-1-[2-(4-nitrophenyl)ethyl]-3-propyluracil (6) to yield 3-[2-(4-nitrophenyl)ethyl]-1-propyl-8-[(thiophen-2-yl)methyl]xanthine. By the method of Example 3, this substance is alkylated with a mixture of 1,2-dichloroethane, sodium carbonate and 2-(ethylamino)ethanol to yield 7-[2-ethyl(2-hydroxyethyl)amino]ethyl-3-[2-(4-nitrophenyl)ethyl]-1-propyl-8-[(thiophen-2-yl)methyl]xanthine. By the method of Example 4 this substance is reduced with hydrazine hydrate or hydrogen gas in the presence of a palladium catalyst to yield 3-[2-(4-aminophenyl)ethyl]-7-[2-ethyl(2-hydroxyethyl)amino]ethyl-1-propyl-8-[(thiophen-2-yl)methyl]xanthine free base. The corresponding dihydrochloride salt is then made on exposure to an excess of hydrogen chloride in solution.