Reacción #48910

Ecuación de reacción

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

Disolventes

dichloromethane

HCl

Condiciones de reacción

Tratamiento posterior

1. 1
   Extracciónextracted with dichloromethane (40 mL×2)
2. 2
   OtroThe combined extracts were dried
3. 3
   Filtraciónfiltered
4. 4
   Concentraciónconcentrated
5. 5
   Otropurified by silica gel chromatography (4:1→1:1; hexanes:ethyl acetate)

Procedimiento

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.

Fuente