Anisole
| Anisole | |
|---|---|
| methoxybenzene | |
| Other names anisole and phenoxymethane | |
| style="background: #F8EABA; text-align: center;" colspan="2" | Identifiers | |
| CAS number | 100-66-3 
|
| SMILES | Script error: No such module "collapsible list". |
| style="background: #F8EABA; text-align: center;" colspan="2" | Properties | |
| Molecular formula | C7H8O |
| Molar mass | 108.14 g/mol |
| Density | 0.995 g/cm³ |
| Melting point |
−37 °C |
| Boiling point |
154 °C |
 (what is this?) (verify)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) | |
| Infobox references | |
Anisole is the organic compound with the formula CH3OC6H5. It is a colorless liquid with a smell reminiscent of anise seed, and in fact many of its derivatives are found in natural and artificial fragrances. The compound is mainly made synthetically and is a precursor to other synthetic compounds.
Contents
Reactivity
Anisole undergoes electrophilic aromatic substitution reaction more quickly than does benzene, which in turn reacts more quickly than nitrobenzene. The methoxy group is an ortho/para directing group, which means that electrophilic substitution preferentially occurs at these three sites. The enhanced nucleophilicity of anisole vs benzene reflects the influence of the methoxy group, which renders the ring more electron-rich. The methoxy group strongly affects the pi cloud of the ring, more so than the inductive effect of the electronegative oxygen.
Illustrative of its nucleophilicity, anisole reacts with acetic anhydride to give 4-methoxyacetophenone:
- CH3OC6H5 + (CH3CO)2O → CH3OC6H4C(O)CH3 + CH3CO2H
Unlike most acetophenones, but reflecting the influence of the methoxy group, methoxyacetophenone undergoes a second acetylation. Many related reactions have been demonstrated. For example, P4S10 converts anisole to Lawesson's reagent, [(CH3O6H4)PS2]2.
The ether linkage is highly stable, but the methyl group can be removed with hydroiodic acid:
- CH3OC6H5 + HI → HOC6H5 + CH3I
Preparation
Anisole is prepared by the Williamson ether synthesis, reacting sodium phenoxide with a methyl bromide and related methylating reagents:[1]
- 2 PhO−Na+ + CH3Br → CH3OC6H5 + NaBr
Applications
Anisole is a precursor to perfumes, insect pheromones, and pharmaceuticals.[2] For example, synthetic anethole is prepared from anisole.
Safety
Anisole is relatively nontoxic with LD50 of 3700 mg/kg in rats.[3]
See also
- Anethole
- Bromoanisole
- Butylated hydroxyanisole
- Ether
- Ethyl phenyl ether
- Phenol
- 2,4,6-Trichloroanisole (cork taint)
References
- ↑ G. S. Hiers and F. D. Hager (1941), "Anisole", Org. Synth.; Coll. Vol., 1: 58 Missing or empty
|title=(help) - ↑ Helmut Fiege, Heinz-Werner Voges, Toshikazu Hamamoto, Sumio Umemura, Tadao Iwata, Hisaya Miki, Yasuhiro Fujita, Hans-Josef Buysch, Dorothea Garbe, Wilfried Paulus “Phenol Derivatives“ in Ullmann's Encyclopedia of Industrial Chemistry, 2002, Wiley-VCH, Weinheim. doi:10.1002/14356007.a19_313
- ↑ MSDS; its main hazard is its flammabiliy.[1]
External links
- International Chemical Safety Card 1014
- Pherobase pheromone database entryar:أنيسول
de:Anisol el:Ανισόλη fr:Anisole it:Anisolo nl:Anisol ja:アニソール no:Anisol pl:Anizol pt:Anisol fi:Anisoli sv:Anisol vi:Anisol zh:苯甲醚
