反応 #48910

反応方程式

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

溶媒

dichloromethane

HCl

反応条件

後処理

1. 1
   抽出extracted with dichloromethane (40 mL×2)
2. 2
   その他The combined extracts were dried
3. 3
   ろ過filtered
4. 4
   濃縮concentrated
5. 5
   その他purified by silica gel chromatography (4:1→1:1; hexanes:ethyl acetate)

実験手順

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.

出典