Benzofuran
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| General | |||||||||||||||||||
| Surname | Benzofuran | ||||||||||||||||||
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| Molecular formula | C 8 H 6 O | ||||||||||||||||||
| Brief description |
colorless liquid with an aromatic odor |
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| properties | |||||||||||||||||||
| Molar mass | 118.13 g mol −1 | ||||||||||||||||||
| Physical state |
liquid |
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| density |
1.10 g cm −3 (25 ° C) |
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| Melting point |
<−18 ° C |
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| boiling point |
173-175 ° C |
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| solubility |
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| Refractive index |
1.5615 (17 ° C) |
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C | |||||||||||||||||||
Benzofuran is a bicyclic heteroaromatic and the oxygen analog of indole . It is made up of a furan ring and a fused benzene ring.
synthesis
In the presence of sodium hydroxide, salicylaldehyde and chloroacetic acid form the sodium salt of 2-formylphenoxyacetic acid , which is converted into the free acid by acidification with hydrochloric acid. This is reacted with acetic anhydride in the presence of glacial acetic acid and sodium acetate to form benzofuran.
Aromaticity
Compared to its heteroaromatic analogs, the aromaticity increases in the following order: benzofuran → benzothiophene → indole .
proof
The spruce chip reaction can be used to detect benzofuran .
See also
- Furan : derivative without a condensed benzene ring .
- Dibenzofuran : derivative with another condensed benzene ring.
- Polychlorinated dibenzofurans (PCDF) .
- Heterocycles , aromatics .
Individual evidence
- ↑ a b entry on benzofuran. In: Römpp Online . Georg Thieme Verlag, accessed on December 28, 2014.
- ↑ a b c d e f Entry on benzofuran in the GESTIS substance database of the IFA , accessed on January 9, 2019(JavaScript required) .
- ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-38.
- ↑ Albert W. Burgstahler, Leonard R. Worden: coumarones (benzofuran) In: Organic Synthesis . 46, 1966, pp. 28-31, doi : 10.15227 / orgsyn.046.0028 ; Coll. Vol. 5, 1973, p. 251 ( PDF ).