Sodium borohydride → 1-Cyclopropylpiperidin-4-ol

To a cold (0° C.) solution of 1-cyclopropyl-piperidin-4-one (1.5 g, 11 mmol, 1.0 eq.) in absolute ethanol was added sodium borohydride (306 mg, 8 mmol, 0.75 eq.). The reaction mixture was stirred at room temperature for 65 h. The mixture was concentrated in vacuo. Ice water (10 mL) was added, followed by an aqueous solution of sodium hydroxide (28% w/w, ca. 10 mL) and dichloromethane (20 mL). The mixture was stirred at room temperature for 2 h. After phase separation, the aqueous layer was extracted with dichloromethane. The combined organic layers were washed with brine, dried over sodium sulfate, filtered and evaporated in vacuo. The crude mixture was purified on silica eluting with DCM/2N NH3 in methanol 93/7, yielding to 1.44 g (95%) of the desired product as a colorless oil. MS (m/e): 423.1 (MH+, 100%)

1. concentrationThe mixture was concentrated in vacuo
2. additionIce water (10 mL) was added
3. stirringThe mixture was stirred at room temperature for 2 h
4. customAfter phase separation
5. extractionthe aqueous layer was extracted with dichloromethane
6. washThe combined organic layers were washed with brine
7. dry with materialdried over sodium sulfate
8. filtrationfiltered
9. customevaporated in vacuo
10. customThe crude mixture was purified on silica eluting with DCM/2N NH3 in methanol 93/7

ORD record

ord-fd9c21e66fa24376a1b48f6e13252009

Source dataset

uspto-grants-2009_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07608617B2