(Diethylamino)sulfur trifluoride → 5,6,7,8-tetrahydro-2-[2,4-dichloro-5-(2-propynyloxy)phenyl]-8-fluoro-1,2,4-triazolo[4,3-alpha]pyridin-3(2H)-one

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).

1. temperatureThe mixture was warmed to room temperature
2. customquenched with ice
3. extractionextracted with dichloromethane
4. dry with materialThe organic layers were dried (MgSO4)
5. concentrationconcentrated under reduced pressure
6. customchromatographed over silica gel
7. washeluting with a 98:2 v
8. additionv mixture of dichloromethane and methanol

ORD record

ord-04601f04a9e04e4b899149b8d86a04b2

Source dataset

uspto-grants-1998_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05728651