Reaktion #10775

Reaktionsgleichung

hydrochloric acid

2-(2-Formyl-5-methoxy-4-thiophen-2-yl-phenoxy)-2-methyl-propionic acid

4-acetylbenzoic acid

lithium methoxide

→

title compound

Ausbeute 85.0%

4-{3E-[2-(1-Carboxy-1-methyl-ethoxy)-4-methoxy-5-thiophen-2-yl-phenyl]-acryloyl}-benzoic acid

Ausbeute 85.0%

Lösungsmittel

dimethylformamide methanol

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   Extraktionextracted with ethyl acetate (3×15 mL)
3. 3
   TrocknenThe combined organic extracts were dried over sodium sulfate
4. 4
   Sonstigeevaporated to dryness
5. 5
   Temperaturwarmed to 60° C.
6. 6
   Sonstigeto obtain complete
7. 7
   workup.DISSOLUTIONdissolution
8. 8
   Temperaturto cool to room temperature
9. 9
   SonstigeThe resulting precipitate was collected
10. 10
    Filtrationon filter paper
11. 11
    Sonstigedried in vacuo

Vorschrift

2-(2-Formyl-5-methoxy-4-thiophen-2-yl-phenoxy)-2-methyl-propionic acid (Ex-59B, 0.12 g, 0.39 mmol) and 4-acetylbenzoic acid (0.064 g, 0.39 mmol) were dissolved in a dimethylformamide-methanol solution (2.7 mL, 7:3). After complete dissolution, lithium methoxide (0.060 g, 1.6 mmol) was added and the resulting bright orange slurry was stirred in the dark at room temperature for 2 h. Upon completion, as determined by HPLC, the mixture was diluted with water (15 mL), acidified with a 1 N hydrochloric acid solution, and extracted with ethyl acetate (3×15 mL). The combined organic extracts were dried over sodium sulfate and evaporated to dryness. The crude oil was taken up in ethyl alcohol (5 mL) and warmed to 60° C. to obtain complete dissolution and allowed to cool to room temperature. The resulting precipitate was collected on filter paper and dried in vacuo to yield 0.15 g (85%) of the title compound as a dark yellow solid, mp 223–225° C. 1H-NMR (300 MHz, DMSO-d6) δ 8.31 (s, 1H), 8.23 (d, 2H, J=8.1 Hz), 8.10 (d, 2H, J=8.1 Hz), 8.06 (s, 1H), 7.95 (d, 1H, J=16.2 Hz), 7.69 (d, 1H, J=3.0 Hz), 7.55 (d, 1H, J=5.1 Hz), 7.14 (dd, 1H, J=5.1, 3.0 Hz), 6.58 (s, 1H), 3.88 (s, 3H), 1.66 (s, 6H). MS (ESI) m/z=467 ([M+H]+, 100%). Anal. Calcd. for C25H22O7S.⅓H2O: C, 63.55; H, 4.84; S, 6.79. Found: C, 63.39; H, 5.02; S, 6.53.

Quelle