5-Hydroxy-1-tetralone
[CAS# 28315-93-7]

Identification

• Classification: Chemical reagent >> Organic reagent >> Fatty ketone (including enol)
• Name: 5-Hydroxy-1-tetralone
• Synonyms: 1,2,3,4-Tetrahydro-5-hydroxynaphthalen-1-one
• Molecular Formula: C₁₀H₁₀O₂
• Molecular Weight: 162.19
• CAS Registry Number: 28315-93-7
• EC Number: 248-958-0
• SMILES: C1CC2=C(C=CC=C2O)C(=O)C1

Properties

• Density: 1.2±0.1 g/cm³ Calc.^*
• Melting point: 206 - 209 °C (Expl.)
• Boiling point: 325.3±31.0 °C 760 mmHg (Calc.)^*
• Flash point: 138.1±17.4 °C (Calc.)^*
• Index of refraction: 1.603 (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335
• Safety Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Eye irritation	Eye Irrit.	2A	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335

Discovery and Applications

5-Hydroxy-1-tetralone is an organic compound belonging to the class of hydroxy-substituted tetralones. Structurally, it consists of a tetralone core—a bicyclic system combining a benzene ring fused to a cyclohexanone ring—with a hydroxyl (–OH) group attached at the 5-position of the aromatic ring. The ketone functionality is located at the 1-position of the cyclohexanone ring, which is adjacent to the aromatic ring fusion.

The tetralone framework serves as an important scaffold in organic synthesis due to its rigid bicyclic structure and the presence of both aromatic and ketone functional groups. Hydroxy substitution at the 5-position modifies the electronic and steric environment of the molecule, often influencing reactivity and potential biological activity. Such substitution can facilitate further functionalization through typical reactions of phenolic groups, including electrophilic aromatic substitution, esterification, and etherification.

Synthesis of 5-hydroxy-1-tetralone can be accomplished by various methods. One common approach involves hydroxylation of 1-tetralone derivatives, typically using selective oxidizing agents or electrophilic substitution reactions directed to the 5-position on the aromatic ring. Alternative routes may include cyclization strategies where the hydroxy group is introduced during ring formation. The synthesis aims to achieve regioselectivity to ensure hydroxylation specifically at the 5-position.

Chemically, 5-hydroxy-1-tetralone exhibits properties characteristic of both phenols and cyclic ketones. The phenolic hydroxyl group can act as a weak acid, donating hydrogen in hydrogen bonding and participating in redox reactions. The ketone group at the 1-position undergoes nucleophilic addition and enolization, allowing participation in condensation and reduction reactions. The combination of these functional groups in a bicyclic structure offers versatility for synthetic modifications.

Applications of 5-hydroxy-1-tetralone include its use as an intermediate in organic synthesis and medicinal chemistry. It serves as a building block for the preparation of more complex molecules, including natural product analogues, pharmaceuticals, and functional materials. Its phenolic and ketone functionalities enable derivatization into compounds with diverse chemical and biological properties.

Analytical characterization of 5-hydroxy-1-tetralone typically involves spectroscopic techniques. Proton nuclear magnetic resonance (²H NMR) spectroscopy identifies aromatic protons, hydroxyl proton signals, and methylene protons adjacent to the ketone. Carbon-13 NMR spectroscopy confirms the presence of ketone carbonyl and aromatic carbons. Infrared (IR) spectroscopy detects characteristic absorption bands for hydroxyl groups (around 3400 cm⁻¹) and ketone carbonyl stretch (near 1700 cm⁻¹). Mass spectrometry provides molecular weight confirmation and fragmentation patterns consistent with the compound’s structure.

Physically, 5-hydroxy-1-tetralone is generally a solid at room temperature, often crystalline in form. It exhibits moderate solubility in organic solvents such as ethanol, methanol, and dichloromethane, while its solubility in water is limited due to its largely hydrophobic bicyclic structure.

In summary, 5-hydroxy-1-tetralone is a hydroxy-substituted bicyclic ketone combining phenolic and ketone functionalities within a tetralone framework. Its chemical properties and structural features make it a valuable intermediate in synthetic organic chemistry and a potential precursor for the development of biologically active compounds.

References

1972. Fluorometric determination of glucose in cerebrospinal fluid and blood by the revised 5-hydroxy-1-tetralone method. Biochemical Medicine, 6(2).
DOI: 10.1016/0006-2944(72)90026-9

1966. Eine Verbesserung der fluorimetrischen Blutglucosebestimmung mit 5-Hydroxytetralon. Fresenius' Zeitschrift für analytische Chemie.
DOI: 10.1007/bf00521767