反应详情

Et3N (2.27 ml. 16. mmol), ethyl 3-aminobenzoate (836 ml, 5.44 mmol) and phosphonitrilic chloride trimer (1.89 g, 5.44 mmol) were sequentially added to a solution of N-(4-bromo-3-methyl-5-isoxazolyl)-2-(carbonyl)thiophene-3-sulfonamide (Example 17) (1 g, 2.27 mmol) in dry THF (20 ml). The reaction was stirred at room temperature for 1 hour and cooled. Water (5 ml) was added to quench the reaction. The resulting solution was concentrated on a rotavap. The residue was diluted with EtOAc and washed with 2N HCl (2×150 ml). The organic layer was dried (MgSO4). The solid was filtered off and the filtrate was concentrated. The residue was treated with 1N NaOH (200 ml) and stirred at 0° C. for 15 minutes. The mixture was then acidified with conc. HCl to pH ~1. The resulting yellow precipitate was filtered off and recrystalized from CH3CN/H2O to give N-(4-bromo-3-methyl-5-isoxazolyl)-2-[N-(3-carboxyphenyl)aminocarbonyl]thiophene-3-sulfonamide (153 mg., 11.6%) as a yellowish powder, m.p. 183°-185° C.

1. temperaturecooled
2. customto quench
3. customthe reaction
4. concentrationThe resulting solution was concentrated on a rotavap
5. additionThe residue was diluted with EtOAc
6. washwashed with 2N HCl (2×150 ml)
7. dry with materialThe organic layer was dried (MgSO4)
8. filtrationThe solid was filtered off
9. concentrationthe filtrate was concentrated
10. additionThe residue was treated with 1N NaOH (200 ml)
11. stirringstirred at 0° C. for 15 minutes
12. filtrationThe resulting yellow precipitate was filtered off
13. customrecrystalized from CH3CN/H2O