Isoamyl Acetoacetate (CAS 2308-18-1) — Mid Note Fragrance Ingredient
Isoamyl Acetoacetate
CAS 2308-18-1
What Is Isoamyl Acetoacetate?
Isoamyl Acetoacetate (CAS 2308-18-1) is an aroma chemical used as a fragrance and flavour ingredient. Its odour is described as apple, apricot and fruity, placing it within the fruity family as a mid note with medium volatility. With a molecular weight of 172.2 (formula C9H16O3), it is handled by perfumers as a building block for compositions where a apple character is desired. The data below is compiled from public chemical and regulatory sources.
Safety Profile
USE WITH AWARENESS
What Does Isoamyl Acetoacetate Smell Like?
The odour profile of Isoamyl Acetoacetate is reported as apple, apricot, fruity, pineapple, tropical, banana, sweet. The dominant facet is its apple character, with the remaining notes adding nuance and complexity. As a mid note it contributes to the heart of a fragrance. Perceived intensity and exact character depend on concentration, the carrier and the surrounding accord.
Scent Profile
Profile derived from public odour-descriptor data; relative, not absolute.
Chemistry & Properties
The Chemistry
Isoamyl Acetoacetate has the molecular formula C9H16O3 and a molecular weight of 172.2 g/mol. Its canonical SMILES representation is CC(C)CCOC(=O)CC(C)=O. Its reported log P (XLogP) of 1.55 indicates a moderately polar molecule, which informs how it partitions in a formula. Physical constants below are drawn from PubChem and EPA CompTox public datasets.
Physical & Chemical Properties
| Molecular Weight | 172.2 g/mol |
|---|---|
| Boiling Point | 221.5 °C |
| Melting Point | -24.38 °C |
| Flash Point | 80.89 °C |
| Density | 1.11 g/cm³ |
| Vapor Pressure | 0.2089 mmHg |
| Water Solubility | 0.02639 g/L |
| XLogP | 1.55 |
Perfumer Guide
Alternatives & Comparisons
Ingredients occupying a similar odour space — useful as substitutes or companions when Isoamyl Acetoacetate is unavailable or restricted.
Shares apple, banana, fruity character — a candidate substitute or companion in the same odour space.
Shares apple, apricot, banana character — a candidate substitute or companion in the same odour space.
Shares sweet, apple, banana character — a candidate substitute or companion in the same odour space.
Safety & Regulatory
⚠ Regulatory Disclaimer
General reference only. IFRA, REACH and EU Cosmetics Regulation standards update periodically. Consult the current IFRA Standards Library before formulating. Not legal or regulatory advice.
IFRA Status
No IFRA restriction recorded in the data set. This is not a guarantee of unrestricted status — always confirm against the current IFRA Standards Library.
GHS Classification
Signal word: Warning
Open Isoamyl Acetoacetate in Fragrance Studio (Pro) for the calibrated vapour-pressure curve, the modelled odour-threshold estimate, and the substitute-matching engine across 2,900+ aromachemicals.
References & Sources
- PubChem Compound Summary (NIH) — search by InChIKey
- EPA CompTox Chemicals Dashboard — physicochemical & fate data
- IFRA Standards Library (49th / 51st Amendment)
Data: PubChem (NIH), EPA CompTox, IFRA. Last reviewed: Jun 2026.
Related Research
- 3,7-Dimethyl-1,6-nonadien-3-yl acetate (CAS 61931-80-4) — Green Top to middle Note Fragrance Ingredient
- Guar gum, 2-hydroxy-3-(trimethylammonio)propyl ether, chloride (CAS 65497-29-2) — Citrus Not applicable Note Fragrance Ingredient
- 4-Methyl-5-vinylthiazole (CAS 1759-28-0) — Sweet Heart Note Fragrance Ingredient
- Methyl ester of rosin (partially hydrogenated) (CAS 8050-15-5) — Woody Base Note Fragrance Ingredient
