Hydrochloric Acid → 6-Methoxy-2,3-dihydro-1-benzofuran-3-one

Chloroacetonitrile (3.5 ml, 55.2 mmol) was added dropwise to a stirred solution containing 3-methoxyphenol (5 ml, 46 mmol) and zinc chloride (6.9 g, 50.6 mmol) in anhydrous dioxane (30 ml) at room temperature. The resulting solution was saturated with dry hydrogen chloride gas. After stirring at room temperature overnight, the yellow precipitate was filtered and washed with anhydrous ether (100 ml). The collected precipitate was dissolved in water (80 ml) and heated to reflux for 1 hour. The solution was allowed to cool to approximately 40° C., and aqueous sodium hydroxide (20% w/v) (7.5 ml) was added. After stirring at that temperature for 30 minutes a pale yellow precipitate had formed. A heterogeneous system was then taken to pH≈7 by addition of hydrochloric acid (1 M). The precipitate was filtered, washed with water, and recrystallized from acetone to give the desired compound as a light yellow powder (4.14 g, 54.8%). 1H NMR: 8 (ppm): 3.85 (OMe); 4.9 (CH2); 6.50-6.46 (2 H-Phenyl); 7.70-7.66 (1 H-Phenyl).

1. filtrationthe yellow precipitate was filtered
2. washwashed with anhydrous ether (100 ml)
3. dissolutionThe collected precipitate was dissolved in water (80 ml)
4. temperatureheated
5. temperatureto reflux for 1 hour
6. temperatureto cool to approximately 40° C.
7. additionaqueous sodium hydroxide (20% w/v) (7.5 ml) was added
8. stirringAfter stirring at that temperature for 30 minutes a pale yellow precipitate
9. customhad formed
10. filtrationThe precipitate was filtered
11. washwashed with water
12. customrecrystallized from acetone

ORD-Eintrag

ord-20c9aa2d223e40049e4f970f6218e367

Quelldatensatz

uspto-grants-2001_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06307070B1