Reaction #65442

Reaction equation

1-[bis(4-fluorophenyl)methyl]piperazine

EDCI

HOBt

6-hydroxy-1,4-benzodioxin -2-carboxylic acid

→

6-Hydroxy-2-{4-[bis-(4-fluorophenyl)methyl]piperazin-1-ylcarbonyl}-1,4-benzodioxin

Yield 85.0%

Solvents

N,N-dimethylformamide

Conditions

Workup

1. 1
   workup.WAITfor 12 hours at room temperature
2. 2
   Concentrationconcentrate the reaction mixture under reduced pressure
3. 3
   ExtractionExtract the resulting amide with diethyl ether
4. 4
   Concentrationafter concentration to dryness
5. 5
   Otherpurify the crude product by chromatography on a silica column (eluant

Procedure

Under a nitrogen atmosphere, add 5.5 mmol of 1-[bis(4-fluorophenyl)methyl]piperazine, 5.5 mmol of EDCI (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide) and 5.5 mmol of HOBt (hydroxybenzotriazole) in succession to a solution at 0° C. of 5 nmml of 6-hydroxy-1,4-benzodioxin -2-carboxylic acid in 25 cm3 of N,N-dimethylformamide. Stir for 2 hours at 0° C. and then for 12 hours at room temperature, and concentrate the reaction mixture under reduced pressure. Extract the resulting amide with diethyl ether and then, after concentration to dryness, purify the crude product by chromatography on a silica column (eluant:petroleum ether then an increasing gradient of ethyl acetate in petroleum ether). 6-Hydroxy-2-{4-[bis-(4-fluorophenyl)methyl]piperazin-1-ylcarbonyl}-1,4-benzodioxin is thereby obtained in a yield of 85%. The product obtained is precipitated from 10 ml of pentane and is then filtered and recrystallised from cyclohexane.

Source