Reaktion #49004

Reaktionsgleichung

water

(E)-3,4-difluoro-2-(2-fluoro-4-iodo-phenylamino)-N-(2-hydroxy-ethoxy)-5-[(2-hydroxy-ethoxyimino)-methyl]-benzamide

trifluoroacetic acid

sodium cyanoborohydride

→

3,4-difluoro-2-(2-fluoro-4-iodo-phenylamino)-N-(2-hydroxy-ethoxy)-5-[(2-hydroxy-ethoxyamino)-methyl]-benzamide

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe progression of the reaction by TLC
2. 2
   Extraktionextracted with ethyl acetate
3. 3
   WaschenThe organic layer was washed with saturated aqueous sodium bicarbonate
4. 4
   Trocknendried over magnesium sulfate
5. 5
   Einengenconcentrated under reduced pressure
6. 6
   SonstigeThe residue was purified by silica gel column chromatography (CH2Cl2/MeOH (15:1))
7. 7
   Sonstigethe resultant crude compound was crystallized from methylene chloride

Vorschrift

To a solution of (E)-3,4-difluoro-2-(2-fluoro-4-iodo-phenylamino)-N-(2-hydroxy-ethoxy)-5-[(2-hydroxy-ethoxyimino)-methyl]-benzamide (3.62 g, 6.70 mmol) obtained in Step B in methanol (100 ml) were added portionwise trifluoroacetic acid (6.5 ml) and sodium cyanoborohydride (3.78 g, 60.2 mmol) over 2 days while monitoring the progression of the reaction by TLC. The reaction mixture was poured into water, and extracted with ethyl acetate. The organic layer was washed with saturated aqueous sodium bicarbonate, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (CH2Cl2/MeOH (15:1)), and the resultant crude compound was crystallized from methylene chloride to give 3,4-difluoro-2-(2-fluoro-4-iodo-phenylamino)-N-(2-hydroxy-ethoxy)-5-[(2-hydroxy-ethoxyamino)-methyl]-benzamide (1.66 g, 46%, as a total of first and second crystals).

Quelle