Réaction #5583

Équation de réaction

2-benzyl-1,4-naphthoquinone

Malononitrile

potassium hydride

hexane

→

product

Rendement 38.0%

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

Rendement 38.0%

Solvants

hexane ethyl acetate

tetrahydrofuran

tetrahydrofuran

Conditions de réaction

Traitement

1. 1
   AutreSolvent was decanted off
2. 2
   workup.ADDITIONwas then added to the slurry dropwise
3. 3
   workup.ADDITIONwas then added dropwise
4. 4
   Températureto cool to room temperature
5. 5
   Autrequenched with methanol (50 ml)
6. 6
   workup.ADDITIONThe mixture was poured into water (100 ml)
7. 7
   Extractionextracted into ethyl acetate (3 x 250 ml)
8. 8
   SéchageThe organic layer was dried (magnesium sulfate)
9. 9
   Autreevaporated to an oil

Mode opératoire

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.

Source