Diacetyl
Aroma Chemical Top Note CAS 431-03-8
Strong, buttery and creamy with a sweet caramel and popcorn character. Extremely powerful, a trace adds a natural butter and pastry effect to gourmand and vanilla accords.
Odor profile
| Note | Top Note |
| Descriptor 1 | Food-like |
| Descriptor 2 | Buttery |
| Descriptor 3 | Creamy |
| Odor Impact1 | 3000 |
| Tenacity1 | 0.8 h |
| Tenacity2 | 44 h |
1 Source: PerfumersWorld
2 Source: The Good Scents Company
Both tenacity figures are blotter life. The two labs use different evaluation protocols, so the numbers are not directly comparable — read them as two independent readings, not as a contradiction.
Identification
| CAS Number | 431-03-8 |
| INCI Name | Diacetyl |
| Category | Aroma Chemical |
| Formula | C4H6O2 |
| Mol. Weight | 86.09 |
| IUPAC Name | butane-2,3-dione |
| InChIKey | QSJXEFYPDANLFS-UHFFFAOYSA-N |
Synonyms
2,3-Butanedione Dimethyl glyoxal, 2,3-Di ketobutane, 2,3-Butane dione, Biacetyl, 2,3-butadione, butan-2,3-dione, 2,3-butandione, butane-2,3-dione, 2,3-butanedione, diacethyl naturel, nat. diacetyl, diacetyl (2, 3 butanedione), diacetyl (natural), diacetyl 99/100% FCC, diacetyl FCC, diacetyl natural, 2,3-diketobutane, dimethyl diketone, dimethyl glyoxal, 2,3-dioxobutane
Physical and chemical data
| Boiling Point | 87.8 °C |
| Melting Point | -2.4 °C |
| Flash Point | 26.7 °C |
| Density | 0.99 |
| Refractive Index | 1.3951 |
| Vapor Pressure | 56.8 [mmHg] |
| LogP | -1.3 |
| Solubility | In water, 200 g/L at 20 °C |
| Appearance | Diacetyl appears as a clear colorless liquid with a strong chlorine-like odor. Flash point 80 °F. Less dense than water. Vapors heavier than air. |
All figures on this page are guide values collected from public reference works and supplier declarations. They differ between batches, origins and qualities. The data sheet of your own supplier is always the authoritative document for the material you actually use.