Reaktion #660012

Reaktionsgleichung

2-[(3-allyloxyphenyl)(1-methylpiperidin-4-yloxy)methyl]benzothiazole

sodium borohydride

→

3-[benzothiazol-2-yl(1-methylpiperidin-4-yloxy)methyl]phenol

Lösungsmittel

tetrahydrofurane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe mixture is stirred for 20 h at room temperature
2. 2
   Filtrationfiltered over a clarcel pad
3. 3
   WaschenThe pad is rinsed with ethyl acetate
4. 4
   WaschenPooled organic phases are washed with aqueous ammonium chloride solution
5. 5
   Trocknensodium hydrogenocarbonate, dried over magnesium sulfate
6. 6
   Einengenconcentrated under reduced pressure
7. 7
   SonstigeThe residue is purified by three column chromatographies over silica gel (twice gradient heptane/ethyl acetate from 95/5 to 80/20, third eluant heptane/dichloromethane 5/1)
8. 8
   EinengenPooled fractions are concentrated under reduced pressure
9. 9
   workup.DISSOLUTIONThe residue is dissolved in methanol
10. 10
    Temperaturrefluxed for 5 h
11. 11
    Einengenconcentrated under reduced pressure
12. 12
    SonstigeThe residue is purified by column chromatography (gradient dichloromethane/methanol/ammonia from 100/0 to 90/10/1)

Vorschrift

To a solution of 2-[(3-allyloxyphenyl)(1-methylpiperidin-4-yloxy)methyl]benzothiazole (example 22) (2.35 g) in tetrahydrofurane (40 mL) is added tetrakistriphenylphosphinepalladium (0.344 g). The mixture is stirred for 5 min at room temperature, then sodium borohydride (0.576 g) is added. The mixture is stirred for 20 h at room temperature, filtered over a clarcel pad. The pad is rinsed with ethyl acetate. Pooled organic phases are washed with aqueous ammonium chloride solution, then sodium hydrogenocarbonate, dried over magnesium sulfate and concentrated under reduced pressure. The residue is purified by three column chromatographies over silica gel (twice gradient heptane/ethyl acetate from 95/5 to 80/20, third eluant heptane/dichloromethane 5/1). Pooled fractions are concentrated under reduced pressure. The residue is dissolved in methanol, refluxed for 5 h and concentrated under reduced pressure. The residue is purified by column chromatography (gradient dichloromethane/methanol/ammonia from 100/0 to 90/10/1) to give 3-[benzothiazol-2-yl(1-methylpiperidin-4-yloxy)methyl]phenol as a beige solid melting at 201° C.

Quelle