Hexane → (R)-tert-butyl 3-(5-chloro-2-methylbenzoyl)piperidine-1-carboxylate

Temperatur

-78 °C

To a solution of 2-bromo-4-chloro-1-methylbenzene (53 g, 0.26 mol) in anhydrous THF (600 mL) at −78° C. under nitrogen was added dropwise a solution of 2.5 M n-BuLi in hexane (103 mL, 0.26 mol). After stirring for 1 hr at −78° C., a solution of the (R)-tert-butyl 3-(methoxy(methyl)carbamoyl)piperidine-1-carboxylate (67 g, 0.246 mol) in anhydrous THF (300 mL) was added dropwise. After addition, the reaction mixture was allowed to warm to rt and stirred for 2 hr. The mixture was quenched with saturated NH4Cl solution (500 mL) and extracted with EtOAc (3×400 mL). The combined organic layers were washed with brine, dried over Na2SO4 and concentrated in vacuo to give crude (R)-tert-butyl 3-(5-chloro-2-methylbenzoyl)piperidine-1-carboxylate (86 g), which was used immediately in the next step without purification.

1. additionAfter addition
2. temperatureto warm to rt
3. stirringstirred for 2 hr
4. customThe mixture was quenched with saturated NH4Cl solution (500 mL)
5. extractionextracted with EtOAc (3×400 mL)
6. washThe combined organic layers were washed with brine
7. dry with materialdried over Na2SO4
8. concentrationconcentrated in vacuo

ORD-Eintrag

ord-7c7df8b5d7a74d5486261e16db256ecc

Quelldatensatz

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08487108B2