Synthesis of 4-(2-fluorophenyl)-7-methoxycoumarin: experimental and computational evidence for intramolecular and intermolecular C–F···H–C bonds
4-(2-Fluorophenyl)-7-methoxycoumarin (6) was synthesized by Pechmann reaction under mild conditions via a three-step reaction. The solution-state 1H NMR spectra of 6 showed a strong intramolecular interaction between F and H5 (JFH = 2.6 Hz) and 13C NMR suggested that this C–F···H–C coupling is a thr...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Beilstein-Institut
2020-02-01
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| Series: | Beilstein Journal of Organic Chemistry |
| Subjects: | |
| Online Access: | https://doi.org/10.3762/bjoc.16.22 |
| Summary: | 4-(2-Fluorophenyl)-7-methoxycoumarin (6) was synthesized by Pechmann reaction under mild conditions via a three-step reaction. The solution-state 1H NMR spectra of 6 showed a strong intramolecular interaction between F and H5 (JFH = 2.6 Hz) and 13C NMR suggested that this C–F···H–C coupling is a through-space interaction. The 2D 19F-{1H} HOESY and 1H-{19F} 1D experiments were done to confirm this F···H interaction. The single crystal X-ray structure and the DFT-optimized structure showed that the fluorinated phenyl ring favors the orientation with the fluorine atom closer to H5 than H3. The X-ray structure also showed the existence of the intermolecular C–F···H–C interaction. |
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| ISSN: | 1860-5397 |