Reaktion #999779

Reaktionsgleichung

tert-butyl piperazine-1-carboxylate

[(1-ethoxycyclopropyl)oxy]trimethylsilane

NaBH3CN

tetrahydrofuran

tert-Butyl 4-cyclopropylpiperazine-1-carboxylate

NaOH

→

title compound

Ausbeute 100.0%

(4-Cyclopropyl-piperazin-1-yl)-(4-morpholin-4-ylmethyl-phenyl)-methanone

Ausbeute 100.0%

Lösungsmittel

acetic acid

methanol

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was cooled to rt
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

tert-Butyl 4-cyclopropylpiperazine-1-carboxylate. A mixture of tert-butyl piperazine-1-carboxylate (75.0 g), tetrahydrofuran (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 rt, 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 give the title compound as a white solid (92 g, 100%). MS (ESI): mass calcd. for C12H22N2O2, 226.17; m/z found, 227.2 [M+H+]. 1H NMR (400 MHz, CDCl3): 3.39 (t, J=5.0 Hz, 4H), 2.55 (t, J=4.9 Hz, 4H), 1.60 (ddd, J=10.3, 6.5, 3.8 Hz, 1H), 1.46 (s, 9H), 0.49-0.38 (m, 4H).

Quelle