(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

HRID 1967

Reaction equation

[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[C:5]([O:9][CH2:10][C:11]#[CH:12])=[CH:4][C:3]=1[N:13]1[C:22](=[O:23])[N:16]2[CH2:17][CH2:18][CH2:19][CH:20](O)[C:15]2=[N:14]1.C(N(S(F)(F)[F:30])CC)C>ClCCl>[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[C:5]([O:9][CH2:10][C:11]#[CH:12])=[CH:4][C:3]=1[N:13]1[C:22](=[O:23])[N:16]2[CH2:17][CH2:18][CH2:19][CH:20]([F:30])[C:15]2=[N:14]1

Participants

Conditions

Temperature: -78 °C

Procedure

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).

Workup

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

Sources & evidence

ORD record: ord-04601f04a9e04e4b899149b8d86a04b2
Source dataset: uspto-grants-1998_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05728651

Linked notes

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