Reaktion #5583

Reaktionsgleichung

2-benzyl-1,4-naphthoquinone

Malononitrile

potassium hydride

hexane

→

product

Ausbeute 38.0%

2-Amino-4-benzyl-3-cyano-5-hydroxynaphtho[1,2-b]furan

Ausbeute 38.0%

Lösungsmittel

hexane ethyl acetate

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeSolvent was decanted off
2. 2
   workup.ADDITIONwas then added to the slurry dropwise
3. 3
   workup.ADDITIONwas then added dropwise
4. 4
   Temperaturto cool to room temperature
5. 5
   Sonstigequenched with methanol (50 ml)
6. 6
   workup.ADDITIONThe mixture was poured into water (100 ml)
7. 7
   Extraktionextracted into ethyl acetate (3 x 250 ml)
8. 8
   TrocknenThe organic layer was dried (magnesium sulfate)
9. 9
   Sonstigeevaporated to an oil

Vorschrift

A mixture of potassium hydride (7.56 g, 63 mmol, 35% oil dispersion) and hexane (250ml) was stirred at room temperature under nitrogen. Solvent was decanted off and substituted with dry tetrahydrofuran (250ml). Malononitrile (4.16 g, 63 mmol), dissolved in tetrahydrofuran (50 ml), was then added to the slurry dropwise. A mixture of 2-benzyl-1,4-naphthoquinone (15.62 g, 63 mmol) and tetrahydrofuran (50 ml) was then added dropwise. The reaction mixture was set at reflux for 2h, allowed to cool to room temperature and quenched with methanol (50 ml). The mixture was poured into water (100 ml) and extracted into ethyl acetate (3 x 250 ml). The organic layer was dried (magnesium sulfate) and evaporated to an oil. Chromatography (silica gel: hexane/ethyl acetate (2 : 1) as eluant) of the oily residue afforded 7.48 g (23 mmol, 38%) of product as green crystals, m.p. 224°-225 ° C.; 1H NMR (d6DMSO): 4.5(s,2H), 7.1-7.6 (m, 7H), 7.9(d, 1H), 9.25(s, 1H); IR (nujol): 3460, 3310, 3240, 3190, 2220; High resolution mass spectrum: calculated 314.1055, measured 314.1061.

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