Reaktion #42597

Reaktionsgleichung

dimethyl 5-bromoisophthalate

N-benzylpiperazine

cesium carbonate

BINAP

→

dimethyl 5-(4-benzylpiperazin-1-yl)isophthalate

Ausbeute 65.3%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeto yield a yellow solution with a white suspension
2. 2
   TemperaturThe reaction mixture was cooled to room temperature
3. 3
   Filtrationvacuum filtered
4. 4
   Waschenthe solid rinsed with fresh toluene
5. 5
   EinengenThe filtrate was then concentrated under reduced pressure
6. 6
   Sonstigeto yield a yellow oil
7. 7
   SonstigePurification by flash chromatography (silica, 80:20 hexanes/ethyl acetate)

Vorschrift

In a sealed tube, a solution of dimethyl 5-bromoisophthalate (5.0 g, 18.3 mmol), N-benzylpiperazine (4.0 mL, 23.0 mmol), and cesium carbonate (8.4 g, 25.7 mmol) in toluene (36 mL) was degassed with nitrogen at room temperature for 20 minutes. Palladium (II) acetate (225 mg, 0.92 mmol) and BINAP (1.7 g, 2.74 mmol) were quickly added under nitrogen and the solution heated to 80° C. overnight to yield a yellow solution with a white suspension. The reaction mixture was cooled to room temperature, vacuum filtered, and the solid rinsed with fresh toluene. The filtrate was then concentrated under reduced pressure to yield a yellow oil. Purification by flash chromatography (silica, 80:20 hexanes/ethyl acetate) gave the desired dimethyl 5-(4-benzylpiperazin-1-yl)isophthalate (4.40 g): ESI MS m/z 369 [M+H]+.

Quelle