Reaktion #157314

Reaktionsgleichung

Sodium hydroxide

9-Borabicyclo[3.3.1]nonane

1-benzyl 4-tert-butyl 2-vinylpiperazine-1,4-dicarboxylate

3-bromopyridine

triphenylphosphine

→

desired product

Ausbeute 63.0%

1-benzyl 4-tert-butyl 2-(2-(pyridin-3-yl)ethyl)piperazine-1,4-dicarboxylate

Ausbeute 63.0%

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeOnce bubbling
2. 2
   Temperaturthe reaction mixture was heated
3. 3
   Temperaturto reflux overnight
4. 4
   workup.ADDITIONthe reaction mixture was diluted with water (200 mL)
5. 5
   Extraktionextracted with EtOAc (3×200 mL)
6. 6
   TrocknenThe combined organics were dried over Na2SO4
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated under reduced pressure
9. 9
   SonstigePurification by column chomatography (10 to 40% EtOAc in Hexane gradient)

Vorschrift

9-Borabicyclo[3.3.1]nonane (0.5M solution in THF, 54 mL, 27 mmol) was added to 1-benzyl 4-tert-butyl 2-vinylpiperazine-1,4-dicarboxylate (2.33 g, 6.73 mmol). After 3 h, 3-bromopyridine (0.99 mL, 10.1 mmol), triphenylphosphine (0.53 g, 2.0 mmol), and tetrakis(triphenylphosphine) palladium(0) (0.311 g, 0.27 mmol) were added. Sodium hydroxide (1N aqueous solution, 16.8 mL, 16.8 mmol) was added slowly. Once bubbling ceased, the reaction mixture was heated to reflux overnight. Upon cooling to rt, the reaction mixture was diluted with water (200 mL) and extracted with EtOAc (3×200 mL). The combined organics were dried over Na2SO4, filtered, and concentrated under reduced pressure. Purification by column chomatography (10 to 40% EtOAc in Hexane gradient) gave 1.79 g (63%) of the desired product as a thick oil. Rf=0.57 in 80% EtOAc/Hexane. LC-MS: RT=7.69 min., [M+H]+=426.2. The material was contaminated with ˜15% triphenylphosphine, and was used without further purification.

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