Reaktion #85462

Reaktionsgleichung

CH2Cl2

N2

3-(t-Butoxycarbonyl)phenylboronic acid

methanesulfonic acid

NaOH

K2CO3

2-Bromo-3-methylpyridine

→

tert-butyl-3-(3-methylpyridin-2-yl)benzoate

Ausbeute 82.0%

Lösungsmittel

water

water

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeto separate
2. 2
   WaschenThe organic phase is then washed with water (3.5 vol)
3. 3
   Extraktionextracted with EtOAc (8 vol)
4. 4
   EinengenThe organic layer is concentrated

Vorschrift

2-Bromo-3-methylpyridine (1.0 eq) is dissolved in toluene (12 vol). K2CO3 (4.8 eq) is added followed by water (3.5 vol) and the mixture heated to 65° C. under a stream of N2 for 1 hour. 3-(t-Butoxycarbonyl)phenylboronic acid (1.05 eq) and Pd(dppf)Cl2.CH2Cl2 (0.015 eq) are then added and the mixture is heated to 80° C. After 2 hours, the heat is turned off, water is added (3.5 vol) and the layers are allowed to separate. The organic phase is then washed with water (3.5 vol) and extracted with 10% aqueous methanesulfonic acid (2 eq MsOH, 7.7 vol). The aqueous phase is made basic with 50% aqueous NaOH (2 eq) and extracted with EtOAc (8 vol). The organic layer is concentrated to afford crude tert-butyl-3-(3-methylpyridin-2-yl)benzoate (82%) that is used directly in the next step.

Quelle