Réaction #48910

Équation de réaction

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

Solvants

dichloromethane

HCl

Conditions de réaction

Traitement

1. 1
   Extractionextracted with dichloromethane (40 mL×2)
2. 2
   AutreThe combined extracts were dried
3. 3
   Filtrationfiltered
4. 4
   Concentrationconcentrated
5. 5
   Autrepurified by silica gel chromatography (4:1→1:1; hexanes:ethyl acetate)

Mode opératoire

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.

Source