Reaction #61526

Reaction equation

4-Furan-2-yl-2,4-dioxo-butyric acid ethyl ester

[5-(5-Chloro-thiophen-2-yl)-isoxazol-3-ylmethyl]-hydrazine

→

1-[5-(5-Chloro-thiophen-2-yl)-isoxazol-3-ylmethyl]-5-furan-2-yl-1H-pyrazole-3-carboxylic acid ethyl ester

Solvents

water

acetic acid

Conditions

Workup

1. 1
   Extractionextracted with ethyl acetate (3×100 ml)
2. 2
   DryingThe combined organic layers were dried over MgSO4
3. 3
   OtherThe solvents were removed under reduced pressure
4. 4
   Otherthe residue was purified by silica gel chromatography
5. 5
   Washeluting with a n-heptane

Procedure

A solution of 550 mg 4-Furan-2-yl-2,4-dioxo-butyric acid ethyl ester and 601 mg [5-(5-Chloro-thiophen-2-yl)-isoxazol-3-ylmethyl]-hydrazine in 10 ml acetic acid was heated to 80° C. for 2 h. Then the reaction mixture was diluted with 20 ml water and extracted with ethyl acetate (3×100 ml). The combined organic layers were dried over MgSO4. The solvents were removed under reduced pressure and the residue was purified by silica gel chromatography eluting with a n-heptane:ethyl acetate gradient 100%->50%.

Source