Reaktion #2178395

Reaktionsgleichung

sodium cyanoborohydride

methyl 4-aminobenzoate

sodium hydrogen carbonate

(5-methoxy-3-methyl-1-benzofuran-2-yl)(phenyl)methanone

sodium hydrogen carbonate

→

compound

Ausbeute 77.1%

methyl 4-{[(5-methoxy-3-methyl-1-benzofuran-2-yl)(phenyl)methyl]amino}benzoate

Ausbeute 77.1%

Lösungsmittel

tetrahydrofuran

acetic acid

methylene chloride

triethylamine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeto quench
2. 2
   Sonstigethe reaction, methylene chloride
3. 3
   Sonstigewas evaporated in an evaporator
4. 4
   Extraktionthe residue was extracted with ethyl acetate
5. 5
   WaschenThe extract was washed with saturated brine
6. 6
   Trocknendried over magnesium sulfate
7. 7
   Einengenconcentrated under reduced pressure
8. 8
   Sonstigeto give a dark brown oil
9. 9
   workup.STIRRINGthe mixture was stirred at room temperature for 2.5 hr
10. 10
    Sonstigeto quench
11. 11
    Sonstigethe reaction
12. 12
    Sonstigethe organic solvent was evaporated in an evaporator
13. 13
    Extraktionthe residue was extracted with ethyl acetate
14. 14
    WaschenThe extract was washed with saturated brine
15. 15
    Trocknendried over magnesium sulfate
16. 16
    Einengenconcentrated under reduced pressure
17. 17
    SonstigeThe residue was purified by silica gel column chromatography (30% ethyl acetate/hexane)

Vorschrift

To a mixture of (5-methoxy-3-methyl-1-benzofuran-2-yl)(phenyl)methanone (2.03 g) synthesized above, methyl 4-aminobenzoate (1.27 g), triethylamine (8.50 mL) and methylene chloride (30 mL) was added titanium (IV) chloride (1.00 mL), and the mixture was stirred under argon atmosphere overnight at room temperature. Saturated aqueous sodium hydrogen carbonate solution was added to quench the reaction, methylene chloride was evaporated in an evaporator, and the residue was extracted with ethyl acetate. The extract was washed with saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure to give a dark brown oil. To a solution (30 mL) of the obtained oil in tetrahydrofuran were added acetic acid (2.18 mL) and sodium cyanoborohydride (955 mg), and the mixture was stirred at room temperature for 2.5 hr. Saturated aqueous sodium hydrogen carbonate solution was added to quench the reaction, the organic solvent was evaporated in an evaporator, and the residue was extracted with ethyl acetate. The extract was washed with saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (30% ethyl acetate/hexane) to give the title object compound (2.36 g, 77%) as a brown solid.

Quelle