Ethanol → 1-Isopropylpiperidin-4-ol

To a cold solution of 1-isopropylpiperidone (purchased at Chemie Brunschwig AG, 100 g, 1.0 eq.) in ethanol (500 mL) was added sodium borohydride (19.3 g, 0.7 eq.) in small portions. The reaction mixture was allowed to warm up to room temperature and was stirred overnight. After concentrating the mixture in vacuo, ice water (1 kg), sodium hydroxide aqueous solution (28% in mass, 0.5 L) and dichloromethane (1 L) were added. The mixture was stirred vigorously for 4 h and the aqueous layer was extracted with dichloromethane. Combined organic layers were washed with brine, dried over sodium sulfate, filtered and purified by fractionated vacuum distillation (20 mbar). One fraction (boiling point 95° C. at 20 mBar) was isolated to yield 61.3 g (60%) of the desired product as colorless oil. MS (m/e): 144.5 (MH+, 100%).

1. concentrationAfter concentrating the mixture in vacuo, ice water (1 kg), sodium hydroxide aqueous solution (28% in mass, 0.5 L) and dichloromethane (1 L)
2. additionwere added
3. stirringThe mixture was stirred vigorously for 4 h
4. extractionthe aqueous layer was extracted with dichloromethane
5. washCombined organic layers were washed with brine
6. dry with materialdried over sodium sulfate
7. filtrationfiltered
8. distillationpurified by fractionated vacuum distillation (20 mbar)
9. customOne fraction (boiling point 95° C. at 20 mBar) was isolated

ORD record

ord-634fa30c922246c1b9d466d4d65c6e67

Source dataset

uspto-grants-2010_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07745479B2