Reaktion #417942

Reaktionsgleichung

bis(pinacolato)diboron

potassium acetate

bromide

3,4-diamino-benzoic acid ethyl ester

→

2

4-methoxycarbonylphenylboronic acid

Lösungsmittel

dioxane

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   WaschenThe organic phase was washed with H2O (20 mL)
2. 2
   Trocknendried over sodium sulfate
3. 3
   Einengenconcentrated in vacuo
4. 4
   SonstigeThe residue was further purified by silica gel column chromatography (haxanes/ethyl acetate=1/4 to 0/1 (v/v))

Vorschrift

Referring to Scheme 11-1, to a solution of the bromide 1 (2.0 g, 4.2 mmol, prepared according to published conditions) in dioxane (60 mL) was added bis(pinacolato)diboron (4.32 g, 17 mmol), Pd(PPh3)4 (0.49 g, 0.42 mmol) and potassium acetate (2.06 g, 21 mmol) under nitrogen atmosphere. The reaction mixture was stirred at 80° C. for 5 h, and then diluted with ethyl acetate (150 mL). The organic phase was washed with H2O (20 mL), dried over sodium sulfate and concentrated in vacuo. The residue was further purified by silica gel column chromatography (haxanes/ethyl acetate=1/4 to 0/1 (v/v)) to give 2 (1.73 g, 79% yield). LC-MS (ESI): m/z 523.3 (M+H)+.

Quelle