Hydrochloric Acid → 1,4'-Bipiperidin-4-ol

4-Oxo-piperidine-1-carboxylic acid tert-butyl ester (20 g) and 4-hydroxypiperidine (6.7 g) were stirred together in dichloroethane (200 ml) with acetic acid (4 ml) at RT for 30 minutes. Sodium triacetoxyborohydride (23 g) was then added and the mixture stirred at RT overnight. The mixture was evaporated to dryness and the residue taken into water, extracted with diethyl ether (3×200 ml), the aqueous was basified to pH 9-10 and extracted with dichloromethane (3×200 ml). The dichloromethane extracts were combined, dried (MgSO4) and evaporated to leave an oil (19 g; same compound as Example 9 step 1). The oil was dissolved in methanol (300 ml) and treated with concentrated hydrochloric acid (5 ml). The mixture was stirred overnight and then evaporated to dryness to leave the title compound as the hydrochloride salt (15 g).

1. customThe mixture was evaporated to dryness
2. extractionextracted with diethyl ether (3×200 ml)
3. extractionextracted with dichloromethane (3×200 ml)
4. dry with materialdried (MgSO4)
5. customevaporated
6. customto leave an oil (19 g; same compound as Example 9 step 1)
7. stirringThe mixture was stirred overnight
8. customevaporated to dryness

ORD record

ord-ce78c81427db4a43bfe750158d2f3136

Source dataset

uspto-grants-2003_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06525070B2