Reaktion #45164

Reaktionsgleichung

ethyl 4-(1,4-diazepan-1-yl)benzoate

(1-ethoxycyclopropoxy)trimethylsilane

acetic acid

sodium cyanoborohydride

→

ethyl 4-(4-cyclopropyl-1,4-diazepan-1-yl)benzoate

Ausbeute 118.0%

Lösungsmittel

tetrahydrofuran

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture was cooled
2. 2
   Filtrationfiltered
3. 3
   Sonstigeevaporated to dryness
4. 4
   workup.ADDITION1N HCl (40 ml) and water (60 ml) were added
5. 5
   Extraktionthe solution extracted with ethyl acetate (3×50 ml)
6. 6
   Extraktionextracted with ethyl acetate (4×50 ml)
7. 7
   WaschenThe organic extracts washed with saturated NaCl (50 ml)
8. 8
   Trocknendried over MgSO4
9. 9
   Filtrationfiltered
10. 10
    Sonstigeevaporated to dryness
11. 11
    SonstigeThe crude product was purified by silica column chromatography
12. 12
    Wascheneluting with a gradient of 0 to 5% MeOH in DCM
13. 13
    SonstigePure fractions were evaporated to dryness

Vorschrift

A solution of ethyl 4-(1,4-diazepan-1-yl)benzoate (0.621 g, 2.5 mmol), (1-ethoxycyclopropoxy)trimethylsilane (2.51 mL, 12.50 mmol) and acetic acid (0.286 mL, 5.00 mmol) in tetrahydrofuran (50 mL), methanol (5 mL) was treated with sodium cyanoborohydride (0.393 g, 6.25 mmol) at 20° C. The resulting solution was stirred at 60° C. for 18 h. The reaction mixture was cooled, filtered and evaporated to dryness. 1N HCl (40 ml) and water (60 ml) were added and the solution extracted with ethyl acetate (3×50 ml). The aqueous layer was basified to pH 10 with solid potassium carbonate and extracted with ethyl acetate (4×50 ml). The organic extracts washed with saturated NaCl (50 ml) and dried over MgSO4, filtered and evaporated to dryness. The crude product was purified by silica column chromatography, eluting with a gradient of 0 to 5% MeOH in DCM. Pure fractions were evaporated to dryness to afford ethyl 4-(4-cyclopropyl-1,4-diazepan-1-yl)benzoate (0.849 g, 118%) as a colourless oil.

Quelle