Reacción #417942

Ecuación de reacción

bis(pinacolato)diboron

potassium acetate

bromide

3,4-diamino-benzoic acid ethyl ester

→

2

4-methoxycarbonylphenylboronic acid

Disolventes

dioxane

ethyl acetate

Condiciones de reacción

Tratamiento posterior

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

Procedimiento

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)+.

Fuente