反应详情

To a suspension of toluene-4-sulfonic acid 3-cyclopropyl-8-methyl-1-(3-nitrophenyl)-2,4,7-trioxo-1,2,3,4,7,8-hexahydro-pyrido[2,3-d]pyrimidin-5-yl ester 12 (21 g) obtained in Step 6 in tetrahydrofuran was added stannous chloride dihydrate (45 g), and the mixture was stirred at room temperature for 4 hrs. The reaction mixture was alkalified with saturated aqueous sodium hydrogen carbonate, an insoluble inorganic product was filtered off by suction using celite as a filtration aides, and the filtrate was extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography (chloroform:acetone=9:1) to give toluene-4-sulfonic acid 1-(3-aminophenyl)-3-cyclopropyl-8-methyl-2,4,7-trioxo-1,2,3,4,7,8-hexahydro-pyrido[2,3-d]pyrimidin-5-yl ester 13 (15 g, 74%) as a white solid.

1. filtrationan insoluble inorganic product was filtered off by suction
2. filtrationas a filtration aides
3. extractionthe filtrate was extracted with ethyl acetate
4. washThe organic layer was washed with brine
5. dry with materialdried over anhydrous magnesium sulfate
6. concentrationconcentrated under reduced pressure
7. customThe residue was purified by column chromatography (chloroform:acetone=9:1)