Reaktion #61780

Reaktionsgleichung

HCl

lithium aluminium hydride

6-(4-Fluoro-phenyl)-2-methyl-nicotinic acid ethyl ester

sodium chloride

→

[6-(4-Fluor-phenyl)-2-methyl-pyridin-3-yl]-methanol

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was cooled to 0° C.
2. 2
   workup.STIRRINGThe mixture was stirred overnight at room temperature (r.t.)
3. 3
   Temperaturcooled to 0° C
4. 4
   workup.STIRRINGstirring
5. 5
   workup.WAITcontinued for 60 min
6. 6
   FiltrationPrecipitated salts were filtered off
7. 7
   Waschenwashed with THF
8. 8
   SonstigeThe combined THF-solutions were evaporated
9. 9
   Extraktionthe residue extracted twice with ethyl acetate
10. 10
    TrocknenThe organic phase was dried (sodium sulphate)
11. 11
    Sonstigeevaporated
12. 12
    SonstigeThe orange resin crystallized after a short time
13. 13
    workup.STIRRINGwas stirred with ethyl acetate/n-heptane 1:3
14. 14
    Sonstigeisolated by filtration
15. 15
    Waschenwashed with tert-butyl-methyl ether
16. 16
    Sonstigedried
17. 17
    SonstigeThe combined mother liquor from the washings was evaporated
18. 18
    workup.ADDITIONthe crystalline precipitate treated as above

Vorschrift

4.67 g (123 mmol) lithium aluminium hydride was suspended in 220 ml tetrahydrofuran (THF) and stirred for 20 min. at room temperature. The mixture was cooled to 0° C. and a solution of 15.95 g (61.5 mmol) 6-(4-Fluoro-phenyl)-2-methyl-nicotinic acid ethyl ester (WO 03/068749) in 100 ml added within 15 min. at the same temperature. The mixture was stirred overnight at room temperature (r.t.) and cooled to 0° C. 200 ml of saturated sodium chloride solution were added drop by drop and stirring continued for 60 min. Concentrated HCl was added carefully to adjust the pH to 5. Precipitated salts were filtered off and washed with THF. The combined THF-solutions were evaporated and the residue extracted twice with ethyl acetate. The organic phase was dried (sodium sulphate) and evaporated. The orange resin crystallized after a short time, was stirred with ethyl acetate/n-heptane 1:3, isolated by filtration, washed with tert-butyl-methyl ether and dried. The combined mother liquor from the washings was evaporated and the crystalline precipitate treated as above. The combined yield was 9.25 g (69%) of pale yellow powder.

Quelle