Reaktion #473946

Reaktionsgleichung

2-methyl-4-nitro-5-isopropoxy-phenylboronic acid pinacol ester

4-Trifluoromethanesulfonyloxy-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester

Cs2CO3

→

4-(5-Isopropoxy-2-methyl-4-nitro-phenyl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester

Lösungsmittel

DME H2O

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturAfter cooling to room temperature
2. 2
   Filtrationthe reaction is filtered through Celite
3. 3
   workup.ADDITIONthe filtrate is diluted with 100 mL of EtOAc
4. 4
   Waschensequentially washed with H2O, brine
5. 5
   Einengenfinally concentrated in vacuo
6. 6
   SonstigeThe crude product is purified by silica gel flash chromatography (5%-15% EtOAc in Hexanes as eluent)

Vorschrift

To a solution of 2-methyl-4-nitro-5-isopropoxy-phenylboronic acid pinacol ester (2.04 g, 6.4 mmol) and 4-Trifluoromethanesulfonyloxy-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester (3.2 g, 9.6 mmol) in 110 mL of DME/H2O (10:1 V/V) is added Pd(PPh3)4 (365 mg, 0.32 mmol) and Cs2CO3 (4.2 g, 12.8 mmol). The reaction mixture is heated under N2 at 80° C. overnight. After cooling to room temperature, the reaction is filtered through Celite and the filtrate is diluted with 100 mL of EtOAc, sequentially washed with H2O, brine, and finally concentrated in vacuo. The crude product is purified by silica gel flash chromatography (5%-15% EtOAc in Hexanes as eluent) to afford 4-(5-Isopropoxy-2-methyl-4-nitro-phenyl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester as a yellow oil. 1H NMR (CD3OD, 400 Mz): 7.59 (s, 1H), 6.96 (s, 1H), 5.67 (broad s, 1H), 4.73 (m, 1H), 4.06 (m, 2H), 3.65 (m, 2H), 2.37 (m, 2H), 2.25 (s, 3H), 1.50 (s, 9H), 1.33 (d, J=6.0 Hz, 6H).

Quelle