Reaction #1563936

Reaction equation

K2CO3

1-amino-4-((tert-butoxycarbonyl)amino)-3-fluoropyridin-1-ium 2,4-dinitrophenolate

Ethyl propiolate

→

title compound

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

Solvents

THF

Conditions

Workup

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITwas continued at 28° C. for 16 hr
3. 3
   OtherReaction mixture
4. 4
   Filtrationwas filtered
5. 5
   Otherto remove the salt, filtrate
6. 6
   Othercollected
7. 7
   workup.ADDITIONwas diluted with EtOAc
8. 8
   Washwashed it with water
9. 9
   Dryingdried over anhydrous sodium sulphate
10. 10
    Concentrationconcentrated under reduced pressure
11. 11
    Otherto afford crude
12. 12
    OtherThe crude obtained
13. 13
    Otherwas purified by column purification (using 60-120 silicagel and 10% EtOAc in Hexane as eluant)

Procedure

K2CO3 (36.96 g, 267 mmol) was added to a solution of 1-amino-4-((tert-butoxycarbonyl)amino)-3-fluoropyridin-1-ium 2,4-dinitrophenolate (50 g, 121 mmol) in THF (500 mL) at 28° C. and continued stirring at same temperature for 30 min. Ethyl propiolate (14.3 g, 145 mmol) was added to above solution and stirring was continued at 28° C. for 16 hr. Reaction mixture was filtered to remove the salt, filtrate collected was diluted with EtOAc washed it with water followed by brine, dried over anhydrous sodium sulphate and concentrated under reduced pressure to afford crude. The crude obtained was purified by column purification (using 60-120 silicagel and 10% EtOAc in Hexane as eluant) to afford the title compound.

Source