Reaction #1563937

Reaction equation

ethyl 5-((tert-butoxycarbonyl)amino)-4-fluoropyrazolo[1,5-a]pyridine-3-carboxylate

TFA

→

title compound

Yield 98.8%

3-(ethoxycarbonyl)-4-fluoropyrazolo[1,5-a]pyridin-5-aminium 2,2,2-trifluoroacetate

Yield 98.8%

Solvents

DCM

Conditions

Workup

1. 1
   Otherreaction mass
2. 2
   Concentrationwas concentrated at temperature below 40° C. under reduced pressure

Procedure

To a solution of ethyl 5-((tert-butoxycarbonyl)amino)-4-fluoropyrazolo[1,5-a]pyridine-3-carboxylate (7 g, 21 mmol) in DCM (60 mL), TFA (12 g, 108 mmol) was added at 0-5° C. drop wise over a period of 30 min, then stirred at room temperature for 2 hrs, reaction mass was concentrated at temperature below 40° C. under reduced pressure to afford the title compound (7 g) which was used in the next step without further purification, MS m/z 223.2 (M+)

Source