반응 #2063

반응 방정식

5,6,7,8-tetrahydro-2-[2,4-dichloro-5-(2-propynyloxy)phenyl]-8-hydroxy-1,2,4-triazolo[4,3-α]pyridin-3(2H)-one

diethylaminosulfur trifluoride

→

title product

수율 90.2%

5,6,7,8-tetrahydro-2-[2,4-dichloro-5-(2-propynyloxy)phenyl]-8-fluoro-1,2,4-triazolo[4,3-α]pyridin-3(2H )-one

수율 90.2%

용매

dichloromethane

반응 조건

후처리

1. 1
   온도The mixture was warmed to room temperature
2. 2
   기타quenched with ice
3. 3
   추출extracted with dichloromethane
4. 4
   건조The organic layers were dried (MgSO4)
5. 5
   농축concentrated under reduced pressure
6. 6
   기타chromatographed over silica gel
7. 7
   세척eluting with a 98:2 v
8. 8
   workup.ADDITIONv mixture of dichloromethane and methanol

실험 절차

To a solution of 300 mg (0.847 mmol) of 5,6,7,8-tetrahydro-2-[2,4-dichloro-5-(2-propynyloxy)phenyl]-8-hydroxy-1,2,4-triazolo[4,3-α]pyridin-3(2H)-one in 10 mL of dichloromethane was added 123 mL (0.930 mmol) of diethylaminosulfur trifluoride (DAST) at -78° C. The reaction mixture was stirred at -78° C. for 4h. The mixture was warmed to room temperature, quenched with ice, and extracted with dichloromethane. The organic layers were dried (MgSO4), and concentrated under reduced pressure. The crude product was flash chromatographed over silica gel, eluting with a 98:2 v:v mixture of dichloromethane and methanol to give 272 mg of the title product of Step 4 as a yellow solid. 19F NMR (CDCl3, 300 MHz) δ-172; 1H NMR (CDCl3, 300 MHz) δ 7.55 (s,1H), 7.2 (s,1H), 5.6, 5.5 (2m, J=70 Hz,1H), 4.8 (s,2H), 4.0 (m,1H), 3.55 (m,1H), 2.6 (m,1H), 2.5-1.8 (m,4H).

출처