4-Hydroxybenzaldehyde
Chemical compound
From Wikipedia, the free encyclopedia
4‑Hydroxybenzaldehyde (para‑hydroxybenzaldehyde) is an organic compound with the formula C6H4OH(CHO).[4][5] Along with 2-hydroxybenzaldehyde and 3-hydroxybenzaldehyde, it is one of the three isomers of hydroxybenzaldehyde.
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| Names | |
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| Preferred IUPAC name
4-Hydroxybenzaldehyde | |
| Other names
p-Hydroxybenzaldehyde, 4-formylphenol[1] | |
| Identifiers | |
3D model (JSmol) |
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| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| DrugBank | |
| ECHA InfoCard | 100.004.182 |
| KEGG | |
PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| C7H6O2 | |
| Molar mass | 122.123 g·mol−1 |
| Appearance | yellow to tan powder |
| Density | 1.129 g/cm3 (130 °C)[1] |
| Melting point | 116 °C (241 °F; 389 K)[1] |
| Boiling point | 310 to 311 °C (590 to 592 °F; 583 to 584 K) |
| 12.9 g/L[2] | |
| Acidity (pKa) | 7.61 (25 °C)[3] |
| −78.0·10−6 cm3/mol | |
Refractive index (nD) |
1.57051 (130 °C)[1] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis, reactions, uses
4-Hydroxybenzaldehyde is prepared by reaction of phenol with chloroform, which gives isomeric hydroxybenzal chlorides. Hydrolysis of the C-Cl bonds gives the aldehyde.[5]
4-Hydroxybenzaldehyde is a precursor to 4-hydroxyphenylglycine, which is itself a precursor to penicillins. In the Dakin oxidation, 4-hydroxybenzaldehyde reacts with hydrogen peroxide in base to form hydroquinone.
Metabolism and occurrence
p-Hydroxybenzaldehyde dehydrogenase is an enzyme found in carrots (Daucus carota).[6]
4-Hydroxybenzaldehyde is found in the orchids Gastrodia elata,[7] Galeola faberi,[8] and the Vanilla orchids.
See also
- Salicylaldehyde (2-hydroxybenzaldehyde)