Реакция #48910

Уравнение реакции

Na2S2O3

Trifluoroacetic anhydride

8-(cyclopentyloxy)-4-(3,5-dichloropyridin-4-ylamino)-7-methoxy-2H-chromen-2-one

urea•H2O2

→

8-(cyclopentyloxy)-4-(3,5-dichloropyridin-4-ylamino)-3-hydroxy-7-methoxy-2H-chromen-2-one

Растворители

dichloromethane

HCl

Условия реакции

Обработка

1. 1
   Экстракцияextracted with dichloromethane (40 mL×2)
2. 2
   ДругоеThe combined extracts were dried
3. 3
   Фильтрацияfiltered
4. 4
   Концентрированиеconcentrated
5. 5
   Другоеpurified by silica gel chromatography (4:1→1:1; hexanes:ethyl acetate)

Методика

Trifluoroacetic anhydride (0.04 mL, 0.29 mmol) was added to a solution of 8-(cyclopentyloxy)-4-(3,5-dichloropyridin-4-ylamino)-7-methoxy-2H-chromen-2-one (42 mg, 0.1 mmol, Example 3), urea•H2O2 (28.5 mg, 0.3 mmol), and dichloromethane (2 mL) at rt under N2. After 1.5 h, sat'd Na2S2O3 (8 mL) was added, and the mixture was stirred vigorously for 15 min. The reaction was then diluted with 0.5N HCl (40 mL), and extracted with dichloromethane (40 mL×2). The combined extracts were dried, filtered, concentrated, and purified by silica gel chromatography (4:1→1:1; hexanes:ethyl acetate) to give 8-(cyclopentyloxy)-4-(3,5-dichloropyridin-4-ylamino)-3-hydroxy-7-methoxy-2H-chromen-2-one: 1H NMR (400 MHz, DMSO-d6): δ 9.30 (s, 1H), 8.42 (s, 2H), 8.40 (s, 1H), 7.59 (d, 1H), 7.12 (d, 1H), 4.84 (m, 1H), 3.86 (s, 3H), 1.90-1.50 (m, 8H); MS (ESI): 436.9.

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