Reaktion #41836

Reaktionsgleichung

NaOH

tert-butyl piperazine-1-carboxylate

[(1-ethoxycyclopropyl)oxy]trimethylsilane

NaBH3CN

→

title compound

tert-Butyl 4-cyclopropylpiperazine-1-carboxylate

Lösungsmittel

acetic acid

methanol

THF

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was cooled to room temperature
2. 2
   workup.STIRRINGwas further stirred for 15 min
3. 3
   EinengenThe mixture was concentrated
4. 4
   Extraktionthe remaining aqueous solution was extracted with CH2Cl2 (500 mL)
5. 5
   WaschenThe organic layer was washed with 1 N NaOH (500 mL)
6. 6
   ExtraktionThe combined aqueous layers were extracted with CH2Cl2 (150 mL)
7. 7
   WaschenThe combined organic layers were washed with brine (400 mL)
8. 8
   Trocknendried (Na2SO4)
9. 9
   Einengenconcentrated

Vorschrift

A mixture of tert-butyl piperazine-1-carboxylate (75.0 g), THF (500 mL), methanol (500 mL), [(1-ethoxycyclopropyl)oxy]trimethylsilane (161 mL), NaBH3CN (38.0 g), and acetic acid (37 mL) was heated at 60° C. for 5 h. The mixture was cooled to room temperature, treated with water (30 mL) and stirred for 5 min. The mixture was then treated with 1 N NaOH (130 mL) and was further stirred for 15 min. The mixture was concentrated, and the remaining aqueous solution was extracted with CH2Cl2 (500 mL). The organic layer was washed with 1 N NaOH (500 mL). The combined aqueous layers were extracted with CH2Cl2 (150 mL). The combined organic layers were washed with brine (400 mL), dried (Na2SO4), and concentrated to yield the title compound as a white solid.

Quelle