Diisopropylamine → N-(4-isopropoxyphenyl)-2-(1-benzyl-4-hydroxypiperidin-4-yl)acetamide

Temperature

-50 °C

Sodium hydride (60% dispersion in oil; 1.99 g) was added to an anhydrous tetrahydrofuran solution (80 mL) of 4′-isopropoxyacetanilide (8.0 g) under nitrogen atmosphere while cooling with ice-water, followed by stirring at the intact temperature for 1 hour. The reaction solution was cooled to −50° C. and added with an anhydrous tetrahydrofuran solution (80 mL) of lithium diisopropylamide prepared from diisopropylamine (11.6 mL) and n-butyl lithium (1.6M hexane solution; 51.8 mL), followed by stirring at −50 to −30° C. for 1 hour. An anhydrous tetrahydrofuran solution (40 mL) of 1-benzylpiperidin-4-one (7.83 g) was added to the reaction solution above at −30° C., and the mixture was stirred −30° C. for 30 minutes, and under cooling with ice-water for 2 hours. The reaction solution was poured into ice-water, and the aqueous solution was extracted with ethyl acetate. The organic layer was sequentially washed with water and saturated brine, dried over anhydrous sodium sulfate, and the solution was distilled off under reduced pressure. The residue obtained was purified by silica gel column chromatography (elution solvent; methylene chloride:methanol=90:10 to 75:25) to obtain the titled compound (10.3 g).

1. stirringby stirring at −50 to −30° C. for 1 hour
2. stirringthe mixture was stirred −30° C. for 30 minutes
3. extractionthe aqueous solution was extracted with ethyl acetate
4. washThe organic layer was sequentially washed with water and saturated brine
5. dry with materialdried over anhydrous sodium sulfate
6. distillationthe solution was distilled off under reduced pressure
7. customThe residue obtained
8. customwas purified by silica gel column chromatography (elution solvent; methylene chloride:methanol=90:10 to 75:25)

ORD record

ord-6c9a057a7ed74c278ff07bc8ae712822

Source dataset

uspto-grants-2004_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06710060B2