Ethanol → Ethyl 5-chloro-3-fluoropicolinate

HRID 650475

Reaktionsgleichung

Cl[C:2]1[C:7]([F:8])=[CH:6][C:5]([Cl:9])=[CH:4][N:3]=1.[CH2:10]([OH:12])C.[C]=[O:14].C(N([CH2:20][CH3:21])CC)C>[Cl-].[Cl-].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[Pd+2]>[CH2:20]([O:14][C:10]([C:2]1[C:7]([F:8])=[CH:6][C:5]([Cl:9])=[CH:4][N:3]=1)=[O:12])[CH3:21]

Komponenten

Reaktionsbedingungen

Temperatur: 90 °C

Versuchsvorschrift

An autoclave is charged with 31.4 g of 2,5-dichloro-3-fluoropyridine, 400 ml of dry ethanol, 27.8 ml of triethylamine and 3.5 g of palladium bis(triphenylphosphine) dichloride (PdCl2(PPh3)2) and then a pressure of 180 bars is applied with carbon monoxide. The mixture is maintained at 90° C. for 4 days. After cooling and releasing the pressure, a further 3.5 g of PdCl2(PPh3)2 are added, a pressure of 130 bars is applied with carbon monoxide, and the mixture is maintained at 90° C. for 3 days, after which it is cooled to 25° C., the pressure is released and the mixture is discharged. After concentration in vacuo, absorption from ethyl acetate onto silica gel is carried out. The silica gel is applied to a flash chromatography column (silica gel) and then eluted with n-hexanelethyl acetate 3/1. 24.3 g of the desired target compound having a melting point of 48-50° C. are obtained.

Aufarbeitung

temperatureAfter cooling
temperaturethe mixture is maintained at 90° C. for 3 days
temperatureafter which it is cooled to 25° C.
concentrationAfter concentration
customin vacuo, absorption from ethyl acetate onto silica gel
washeluted with n-hexanelethyl acetate 3/1
customare obtained

Quellen und Nachweise

ORD-Eintrag: ord-060f7c916bff46c7a17eff68139ff51d
Quelldatensatz: uspto-grants-2001_08
DOI: 10.6084/m9.figshare.5104873.v1
Patentnummer: US06274536B1

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