Reaktion #307624

Reaktionsgleichung

4-(2-chloropyridin-3-yl)-piperazine-1-carboxylic acid t-butyl ester

4-fluorophenylboronic acid

potassium phosphate

→

4-[2-(4-fluorophenyl)-pyridin-3-yl]-piperazine-1-carboxylic acid t-butyl ester

Ausbeute 28.0%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturCool to room temperature
2. 2
   Einengenconcentrate
3. 3
   Sonstigepartition the residue between ethyl acetate and 1 N sodium hydroxide (pH=11)
4. 4
   TrocknenDry (sodium sulfate)
5. 5
   Filtrationfilter
6. 6
   Einengenconcentrate
7. 7
   Sonstigepurify
8. 8
   Waschen(silica gel chromatography, eluting with 20:80 ethyl acetate:hexanes)

Vorschrift

Dissolve 4-(2-chloropyridin-3-yl)-piperazine-1-carboxylic acid t-butyl ester (2.7 g, 9.1 mmol) in toluene (30 mL). Add 4-fluorophenylboronic acid (1.92 g, 13.70 mmol) followed by bis(dibenzylideneacetone)palladium(0) (0.42 g, 0.46 mmol), 1,2,3,4,5-pentaphenyl-1′-(di-t-butylphosphino)ferrocene (CTC-Q-PHOS) (0.65 g, 0.91 mmol) and potassium phosphate (5.8 g, 27.3 mmol). Heat the reaction mixture at 100° C. for 23 hr. Cool to room temperature, concentrate and partition the residue between ethyl acetate and 1 N sodium hydroxide (pH=11). Dry (sodium sulfate), filter, concentrate and purify (silica gel chromatography, eluting with 20:80 ethyl acetate:hexanes), to give 4-[2-(4-fluorophenyl)-pyridin-3-yl]-piperazine-1-carboxylic acid t-butyl ester (28%). MS (ES): m/z=358 [M+H].

Quelle