Cuminaldehyde (122-03-2) Physical and Chemical Properties
Cuminaldehyde
An aromatic benzaldehyde used as a flavor and fragrance ingredient and as an intermediate in specialty chemical synthesis, relevant to procurement, formulation and analytical QC.
| CAS Number | 122-03-2 |
| Family | Benzaldehydes |
| Typical Form | Colorless to pale yellow liquid |
| Common Grades | EP, FCC, JP |
Cuminaldehyde is an aromatic aldehyde belonging to the benzaldehyde structural class; it is formally 4‑isopropylbenzaldehyde, a para‑substituted benzaldehyde bearing an isopropyl (propan‑2‑yl) substituent on the aromatic ring. The molecule combines a conjugated carbonyl chromophore directly attached to the aromatic pi system with a nonpolar aliphatic substituent, producing a balance of conjugation-stabilized reactivity at the formyl group and appreciable hydrophobic surface area from the isopropyl group.
Electronically, the aromatic ring conjugation delocalizes the aldehyde π system, while the alkyl substituent is weakly electron‑donating by hyperconjugation; this modestly reduces the electrophilicity of the carbonyl relative to unsubstituted benzaldehyde. Physicochemically the compound is a low‑polarity, moderately lipophilic liquid (limited aqueous solubility, measurable octanol–water partitioning) with a characteristic pungent, herbaceous odor typical of many volatile aromatic aldehydes. As a member of common flavor and fragrance classes, it is moderately volatile and chemically reactive in canonical aldehyde transformations (oxidation, nucleophilic addition, condensation).
Cuminaldehyde occurs naturally as a component of various essential oils (notably cumin) and is used industrially as a fragrance and flavouring ingredient and as an intermediate in fine‑chemical manufacture; it also exhibits reported insecticidal activity and is encountered in formulations where aroma and biological activity are desired. Common commercial grades reported for this substance include: EP, FCC, JP.
Basic Physical Properties
Density
0.973-0.981 \(\mathrm{g\,mL^{-1}}\).
This density range (just below unity) is typical for substituted aromatic liquids of this molar mass and reflects the combination of an aromatic ring and a small aliphatic substituent; the value will vary slightly with temperature and purity (impurities and residual solvents).
Melting Point
No experimentally established value for this property is available in the current data context.
Boiling Point
235.5 \(\,^\circ\mathrm{C}\).
A relatively high boiling point for a monoaromatic volatile reflects the molecular weight (148.20) and the absence of strong associative hydrogen bonding; the high value corresponds to relatively low vapor pressure at ambient temperature.
Vapor Pressure
No experimentally established value for this property is available in the current data context.
Flash Point
No experimentally established value for this property is available in the current data context.
Chemical Properties
Solubility and Phase Behavior
- Solubility: 282 mg/L @ 20 \(\,^\circ\mathrm{C}\) (exp).
- Descriptive solubility: insoluble in water; soluble in organic solvents, oils.
- Miscibility: miscible at room temperature (in ethanol).
The low aqueous solubility is consistent with the alkyl substitution and measured lipophilicity (see logP data). Solubility in alcohols and common organic solvents makes the compound suitable for formulation into fragrance and flavor carriers and for use as an intermediate in organic synthesis.
Reactivity and Stability
As an aromatic aldehyde, cuminaldehyde undergoes canonical carbonyl chemistry: nucleophilic addition (e.g., imine/Schiff base formation with amines), oxidation to the corresponding carboxylic acid, and aldol‑type condensations under basic conditions. Conjugation with the aromatic ring moderates but does not prevent reactivity at the formyl carbon. Aldehyde functionality may undergo slow autoxidation or polymerization on prolonged exposure to air, light or heat and can form adducts with nucleophiles; packaging under inert atmosphere and stabilizers are commonly used for storage of reactive aldehydes in practice. The para‑isopropyl substituent imparts steric and electronic effects that influence rates of electrophilic substitution and some carbonyl reactions relative to benzaldehyde.
Thermodynamic Data
Standard Enthalpies and Heat Capacity
No experimentally established value for this property is available in the current data context.
Molecular Parameters
Molecular Weight and Formula
- Molecular formula: \(\ce{C10H12O}\)
- Molecular weight: 148.20
- Exact/monoisotopic mass: 148.088815002
- Heavy atom count: 11
- Complexity: 121
The formula \(\ce{C10H12O}\) corresponds to a monosubstituted benzaldehyde scaffold with one oxygen (the aldehyde) and an isopropyl substituent.
LogP and Polarity
- Computed XLogP: 2.7
- Experimental LogP: 3.170
- Topological polar surface area (TPSA): 17.1 \(\text{Å}^2\)
- Hydrogen bond donor count: 0
- Hydrogen bond acceptor count: 1
- Rotatable bond count: 2
These descriptors indicate moderate lipophilicity and low polarity: the molecule will partition preferentially into organic phases and lipid matrices, and has only a single hydrogen‑bond acceptor (the carbonyl oxygen) and no donors.
Structural Features
Cuminaldehyde is para‑substituted on the benzene ring by an isopropyl group (4‑propan‑2‑ylbenzaldehyde). The conjugation between the aromatic ring and the aldehyde carbonyl stabilizes the formyl π system, influencing spectroscopic properties and reactivity (e.g., reduced carbonyl electrophilicity vs. aliphatic aldehydes). Steric influence from the isopropyl group is modest but can affect approach of reagents at the aromatic positions and modulate odor character and volatility compared with unsubstituted benzaldehyde.
Identifiers and Synonyms
Registry Numbers and Codes
- CAS: 122-03-2
- EC (European Community) number: 204-516-9
- UNII: O0893NC35F
- FEMA Number: 2341
Key structural identifiers:
- InChI: InChI=1S/C10H12O/c1-8(2)10-5-3-9(7-11)4-6-10/h3-8H,1-2H3
- InChIKey: WTWBUQJHJGUZCY-UHFFFAOYSA-N
- SMILES: CC(C)C1=CC=C(C=C1)C=O
Synonyms and Structural Names
Common synonyms and name variants found in industry and supply listings include: 4‑isopropylbenzaldehyde, cuminaldehyde, cuminic aldehyde, p‑isopropyl benzaldehyde, cuminal, cumaldehyde, p‑cumic aldehyde, 4‑propan‑2‑ylbenzaldehyde. (Multiple closely related name forms are used in commercial and analytical contexts.)
Industrial and Commercial Applications
Representative Uses and Industry Sectors
Cuminaldehyde is used as a flavoring and fragrance ingredient and occurs naturally in various essential oils (notably cumin). Typical applications include use as a fragrance ingredient in perfumes and personal care formulations, a flavoring compound in food ingredients, and as an intermediate in the manufacture of fine chemicals and aroma chemicals. Manufacture/commerce activity (aggregated product volume) for recent years is reported as: 2019: <1,000,000 lb; 2018: <1,000,000 lb; 2017: <1,000,000 lb; 2016: <1,000,000 lb. It is also reported to possess insecticidal activity and may be used in products exploiting that property.
Concentration limits for use in finished consumer formulations are applied in industry practice; representative restriction limits given for finished products (selected categories) include: Category 1 (products applied to the lips) 0.085%; Category 2 (products applied to the axillae) 0.025%; Category 3 (products applied to the face/body using fingertips) 0.51%; Category 4 (fine fragrances) 0.47%; Category 6 (products with oral and lip exposure) 0.28%. These limits are used by formulators to manage dermal sensitization risk.
Role in Synthesis or Formulations
As an aromatic aldehyde, cuminaldehyde functions as a synthetic intermediate for producing more complex aromatic derivatives via reduction, oxidation, condensation or reductive amination. In formulations it provides characteristic green, spicy, herbaceous, slightly acid odour notes and is incorporated into blends at low concentrations. The aldehyde function also enables chemical modification to deliver derivatives with altered olfactory profiles or physical properties for use in fine‑chemical applications.
Safety and Handling Overview
Acute and Occupational Toxicity
GHS hazard information commonly reported for technical material includes: H302 — Harmful if swallowed; H317 — May cause an allergic skin reaction. Aggregated hazard classifications reported include Acute toxicity (Oral) — Category 4 and Skin Sensitisation — Category 1B (reported in a subset of supplier notifications). Empirical toxicology summaries indicate that, in animal oral lethal‑dose studies, effects reported include somnolence and gastrointestinal and liver changes; the substance is identified as a skin and strong eye irritant and is classified as harmful by ingestion. Limited human patch test data have produced positive sensitization responses in a small fraction of tested subjects.
Occupational controls should therefore focus on minimizing ingestion, inhalation of aerosols/vapour, and dermal exposure. Use of appropriate protective gloves, goggles, and local exhaust ventilation is recommended in production and handling environments.
Storage and Handling Considerations
Store in a cool, dry, well‑ventilated area away from strong oxidizers and sources of heat or ignition. Keep containers tightly closed and protected from prolonged light exposure to minimize degradation by air oxidation. Handle with standard industrial hygiene measures for reactive aromatic aldehydes: avoid skin contact, avoid inhalation of vapours, and use suitable PPE (gloves, eye protection, and, if required by exposure assessment, respiratory protection). For spill, fire and emergency procedures, and regulatory transport and disposal information consult the product‑specific Safety Data Sheet (SDS) and applicable local legislation.
