Ammonium Chloride → [4-(2-Hydroxy-2-phenyl-2-o-tolyl-ethyl)-pyridin-2-yl]-carbamic acid tert-butyl ester

Temperatur

-78 °C

(4-Methyl-pyridin-2-yl)-carbamic acid tert-butyl ester (300 mg, 1.4 mmol) is dissolved in dry THF (15 mL) and it is cooled down to −78° C. After 1.6 M n-BuLi (4.5 mL, 7.2 mmol) is added at −78° C., the cooling bath is removed and the mixture is stirred at room temperature for 15 min. Then the reaction mixture is cooled down to −78° C. again and phenyl-o-tolyl-methanone (1.3 mL, 7.2 mmol) is added. After the mixture is stirred for 30 min at −78° C., saturated NH4Cl aqueous solution (15 mL) is added and the reaction is warmed up to room temperature. EtOAc (60 mL) is added along with water (50 mL). The mixture is stirred for another 10 min and the aqueous layer is separated, extracted with EtOAc (2×35 ml). The organic layers are combined and concentrated to give the crude product. Purification by silica flash column chromatography using MeOH in DCM (gradient from 0% to 10%) affords 361 mg of the desired product.

1. customthe cooling bath is removed
2. temperatureThen the reaction mixture is cooled down to −78° C. again
3. stirringAfter the mixture is stirred for 30 min at −78° C.
4. temperaturethe reaction is warmed up to room temperature
5. stirringThe mixture is stirred for another 10 min
6. customthe aqueous layer is separated
7. extractionextracted with EtOAc (2×35 ml)
8. concentrationconcentrated
9. customto give the crude product
10. customPurification by silica flash column chromatography

ORD-Eintrag

ord-9f4e2f29d02541fdb765fd40f9aa9751

Quelldatensatz

uspto-grants-2014_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08722709B2