Methoxymethyl-triphenylphosphonium chloride → 5-Chloro-2-(2-methoxyvinyl)-benzoic acid

Temperatur

0 °C

To a cooled (0° C.) slurry of methoxymethyltriphenylphosphonium chloride (39 g) in a mixture of diethyl ether (200 ml) and tert-butanol (50 ml) was added potassium tert-butoxide (12.8 g) portionwise. The resulting mixture was stirred at 0° C. for 1 hour, then a solution of 2-formyl-5-chlorobenzoic acid (prepared as described in J. Org. Chem. 1996, 61, 3402)(10 g) in diethyl ether (50 ml) was added dropwise over 15 minutes. The resulting mixture was stirred for 1 hour at 0° C., then warmed to ambient and stirred for an additional 90 minutes. The mixture was diluted with water (200 ml) and the organic phase removed. The aqueous phase was acidified to pH1 with 1M HCl and extracted with ethyl acetate (3×50 ml). The combined extracts were washed with brine, dried (magnesium sulfate), filtered and concentrated. The residue was purified by flash chromatography (50% ethyl acetate/hexane) to afford the sub-title compound as a yellow solid (9.13 g, 80%): 1H NMR (400 MHz, CDCl3) δ 3.70-3.81 (3H, s), 6.20(0.3 H, d), 6.30 (0.3 H, d), 6.80(0.7 H, d), 7.01 (0.7 H, d), 7.30-8.15 (3H, m).

1. stirringThe resulting mixture was stirred for 1 hour at 0° C.
2. temperaturewarmed
3. stirringstirred for an additional 90 minutes
4. customthe organic phase removed
5. extractionextracted with ethyl acetate (3×50 ml)
6. washThe combined extracts were washed with brine
7. dry with materialdried (magnesium sulfate)
8. filtrationfiltered
9. concentrationconcentrated
10. customThe residue was purified by flash chromatography (50% ethyl acetate/hexane)

ORD-Eintrag

ord-ccf619b49e704885897e7f1659778887

Quelldatensatz

uspto-grants-2011_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08071618B2