反応 #10771

反応方程式

hydrochloric acid

4-Hydroxy-2-methoxy-5-thiophen-2-yl-benzaldehyde

4-acetylbenzoic acid

lithium methoxide

→

title compound

収率 5.0%

4-[3E-(4-Hydroxy-2-methoxy-5-thiophen-2-yl-phenyl)-acryloyl]-benzoic acid

収率 5.0%

溶媒

dimethylformamide methanol

water

ethyl alcohol

反応条件

後処理

1. 1
   workup.ADDITIONwas added
2. 2
   抽出extracted with ethyl acetate (4×25 mL)
3. 3
   乾燥The combined organic extracts were dried over sodium sulfate
4. 4
   その他evaporated to dryness
5. 5
   その他to yield an orange solid
6. 6
   workup.ADDITIONcontaining residual amounts
7. 7
   その他to remove acid impurity
8. 8
   その他the resulting precipitate was collected
9. 9
   ろ過on filter paper
10. 10
    その他dried in vacuo

実験手順

4-Hydroxy-2-methoxy-5-thiophen-2-yl-benzaldehyde (Ex-47B, 0.30 g, 0.86 mmol) and 4-acetylbenzoic acid (0.13 g, 0.86 mmol) were dissolved in a dimethylformamide-methanol solution (6 mL, 7:3). After complete dissolution, lithium methoxide (0.12 g, 3.3 mmol) was added and the resulting red slurry was stirred in the dark at room temperature for 18 h. The mixture was diluted with water (15 mL), acidified with a 1 N hydrochloric acid solution, and extracted with ethyl acetate (4×25 mL). The combined organic extracts were dried over sodium sulfate and evaporated to dryness. The crude oil was subjected to silica gel chromatography (CH2Cl2:MeOH, 20:1) to yield an orange solid containing residual amounts of starting acid. The solid was taken up in ethyl alcohol (5 mL) to remove acid impurity and the resulting precipitate was collected on filter paper and dried in vacuo to yield 0.010 g (5%) of the title compound as an orange solid, mp 243° C. (dec). 1H-NMR (300 MHz, DMSO-d6) δ 8.18–8.23 (m, 3H), 8.06–8.09 (m, 2H), 8.02 (s, 1H), 7.85 (d, 1H, J=15.6 Hz), 7.68 (d, 1H, J=3.6 Hz), 7.47 (d, 1H, J=5.1 Hz), 7.11 (dd, 1H, J=5.1, 3.6 Hz), 6.67 (s, 1H), 4.13 (s, 1H), 3.89 (s, 3H). MS (ESI) m/z=381 ([M+H]30 , 100%). HRMS (ESI) Calcd. for C21H16O5S: 381.0796. Found: 381.0800.

出典