3-Cyclohexene-1-carboxaldehyde
[CAS# 100-50-5]

Identification

• Classification: Chemical reagent >> Organic reagent >> Aromatic aldehyde (containing acetal, hemiacetal)
• Name: 3-Cyclohexene-1-carboxaldehyde
• Synonyms: 1,2,3,6-Tetrahydrobenzaldehyde; 4-Formyl-1-cyclohexene
• Molecular Formula: C₇H₁₀O
• Molecular Weight: 110.15
• CAS Registry Number: 100-50-5
• EC Number: 202-858-3
• SMILES: C1CC(CC=C1)C=O

Properties

• Density: 0.97 g/mL
• Melting point: 1-3 °C
• Boiling point: 163-164 °C
• Refractive index: 1.4745
• Flash point: 57 °C

Safety Data

• Hazard Symbols: GHS02;GHS07 Warning
• Risk Statements: H226-H312-H315-H319-H335
• Safety Statements: P210-P233-P240-P241-P242-P243-P261-P264-P264+P265-P271-P280-P302+P352-P303+P361+P353-P304+P340-P305+P351+P338-P317-P319-P321-P332+P317-P337+P317-P362+P364-P370+P378-P403+P233-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	3	H226
Acute toxicity	Acute Tox.	4	H312
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Serious eye damage	Eye Dam.	1	H318
Skin corrosion	Skin Corr.	1B	H314
Eye irritation	Eye Irrit.	2A	H319
Skin corrosion	Skin Corr.	1A	H314
Acute toxicity	Acute Tox.	4	H332

• Transport Information: UN 2498

Discovery and Applications

3-Cyclohexene-1-carboxaldehyde is an organic compound characterized by a cyclohexene ring with an attached formyl group (-CHO) at the 1-position. This compound, with the molecular formula C₇H₁₀O, belongs to the family of unsaturated aldehydes, which are valuable intermediates in organic synthesis. Its discovery and development were driven by the need for compounds with unique reactivity profiles, especially in the production of fragrances, pharmaceuticals, and fine chemicals.

The synthesis of 3-cyclohexene-1-carboxaldehyde can be achieved through several methods, with one of the most common routes involving the selective oxidation of cyclohexene. This oxidation is typically carried out using mild oxidizing agents that convert the alkene to an aldehyde while preserving the integrity of the cyclohexene ring. Another approach involves hydroformylation reactions, where an alkene is reacted with synthesis gas (a mixture of hydrogen and carbon monoxide) in the presence of a transition metal catalyst to introduce the formyl group.

One of the earliest applications of 3-cyclohexene-1-carboxaldehyde was in the fragrance industry. The compound’s structure allows it to serve as a precursor for various aroma chemicals. Aldehydes are key components in many perfumes and flavorings due to their strong and often pleasant odors. 3-Cyclohexene-1-carboxaldehyde can undergo further chemical transformations to produce compounds with floral, citrus, or woody notes, making it a versatile starting material in the synthesis of fragrances used in consumer products such as perfumes, lotions, and air fresheners.

In the pharmaceutical industry, 3-cyclohexene-1-carboxaldehyde has been explored as a building block for the synthesis of bioactive molecules. The presence of both an alkene and an aldehyde group in its structure allows for a variety of reactions, including condensation, cycloaddition, and reduction, which are useful in the formation of complex molecular architectures. Researchers have investigated its role in the synthesis of compounds with potential therapeutic properties, such as anti-inflammatory agents and intermediates for cardiovascular drugs. Its reactivity makes it valuable in the preparation of chiral intermediates, which are important in the production of enantiomerically pure pharmaceuticals.

In the field of materials science, 3-cyclohexene-1-carboxaldehyde has found application in the preparation of polymers and advanced materials. The compound’s unsaturated nature enables it to participate in polymerization reactions, leading to the formation of specialized polymers with unique properties. Such polymers are used in coatings, adhesives, and elastomers, where the ability to fine-tune mechanical properties is essential. Additionally, the aldehyde group provides sites for further functionalization, allowing for the creation of materials with tailored characteristics, such as improved durability, flexibility, or thermal stability.

Environmental studies concerning 3-cyclohexene-1-carboxaldehyde have focused on its potential impact when released into the environment through industrial processes. As with many aldehydes, this compound can be reactive in the atmosphere, contributing to the formation of photochemical smog or reacting with other atmospheric components. Understanding its environmental fate and behavior is crucial for developing guidelines for its safe handling and use in industrial applications. Toxicological studies have also been conducted to assess its effects on human health, particularly in occupational settings where exposure to aldehydes may occur.

In addition to its industrial uses, 3-cyclohexene-1-carboxaldehyde continues to be an important compound in academic research. Its structure offers opportunities for studying reaction mechanisms, particularly in the areas of organic synthesis and catalysis. Researchers have used it as a model substrate in various experimental studies to develop new catalytic systems or to better understand the principles of organic reactivity. The compound’s versatility ensures that it remains a valuable tool in the development of new synthetic methodologies.

In summary, 3-cyclohexene-1-carboxaldehyde is a multifaceted compound with a broad range of applications in industries such as fragrances, pharmaceuticals, and materials science. Its reactivity and structural features make it a valuable intermediate in the production of complex molecules and advanced materials. As research continues, its role in innovative chemical processes is expected to grow, underscoring its importance in modern organic chemistry.

References

2013. Synthesis of methyl 7-aryl(hetaryl, cyclohexenyl)-10-(1,3-benzodioxol-5-yl)-8-oxo-7,8,9,10,11,12-hexahydro-benzo[b][1,7]phenanthroline-9-carboxylates. Russian Journal of Organic Chemistry, 49(9).
DOI: 10.1134/s1070428013090157

2016. Treatment of an industrial stream containing vinylcyclohexene by the H2O2/UV process. Environmental Science and Pollution Research International, 23(19).
DOI: 10.1007/s11356-016-7120-4

2023. Multicomponent Syntheses of Cycloalka[b]pyridines and Chromenes. Russian Journal of Organic Chemistry, 59(7).
DOI: 10.1134/s1070428023070060