Methyl Naphtyl Ketone Beta
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Methyl Naphtyl Ketone Beta (CAS N° 93-08-3), also known as 2-Acetylnaphthalene, is a synthetic aromatic compound primarily used for its sweet, powdery-floral scent resembling orange blossom. This ketone, supplied by Symrise and known under trade names such as Orenolia, Nerolys, and Orangeol, delivers a powerful and tenacious floral note with mild fruity undertones. It is particularly valued for enhancing exotic floral blends and for its high olfactory persistence, especially in the drydown phase of perfumery compositions.
Premium Synthetic Ingredient for Perfumery
Methyl Naphtyl Ketone Beta (CAS N° 93-08-3), also known as 2-Acetylnaphthalene, is a synthetic aromatic compound primarily used for its sweet, powdery-floral scent resembling orange blossom. This ketone, supplied by Symrise and known under trade names such as Orenolia, Nerolys, and Orangeol, delivers a powerful and tenacious floral note with mild fruity undertones. It is particularly valued for enhancing exotic floral blends and for its high olfactory persistence, especially in the drydown phase of perfumery compositions.
Premium Synthetic Ingredient for Perfumery
Methyl Naphtyl Ketone Beta (CAS N° 93-08-3), also known as 2-Acetylnaphthalene, is a synthetic aromatic compound primarily used for its sweet, powdery-floral scent resembling orange blossom. This ketone, supplied by Symrise and known under trade names such as Orenolia, Nerolys, and Orangeol, delivers a powerful and tenacious floral note with mild fruity undertones. It is particularly valued for enhancing exotic floral blends and for its high olfactory persistence, especially in the drydown phase of perfumery compositions.
Synthetic Ingredient Overview
🏭 Manufacturer: Symrise
🔎 Chemical Name: 2-Acetylnaphthalene
🧪 Synonyms: beta-Methyl naphthyl ketone, 2'-Acetonaphthone, Oranger Crystals, Orangeol, Orenolia, Nerolys (β-isomer)
🧬 Chemical Formula: C₁₂H₁₀O
📂 CAS N°: 93-08-3
📘 FEMA: 2690
⚖️ MW: 170.21 g/mol
📝 Odor Type: Powdery, Floral (Orange Blossom)
📈 Odor Strength: Medium (noted for tenacious drydown)
👃🏼 Odor Profile: Sweet, powdery, very tenacious orange blossom scent; remotely fruity and soft; less harsh than Methyl Anthranilate
👅 Flavor Profile: In dilution, reminiscent of strawberry and grape
⚗️ Uses: Floral modifier in Neroli, Magnolia, Honeysuckle, Frangipani, Sweet Pea, Wisteria; also in imitation Strawberry and Grape flavorings
🧴 Appearance: White crystalline solid
What is Methyl Naphtyl Ketone Beta?
2-Acetylnaphthalene is a synthetic aromatic ketone developed prior to the 1920s and commercially adopted for its orange blossom character in both fragrance and flavor applications. Its structure is unrelated to methyl anthranilate despite shared odor categories. Methyl Naphtyl Ketone Beta offers a significantly softer, rounder profile without harsh phenolic undertones, making it a preferred component in delicate floral accords.
Unlike its alpha-isomer (1-acetylnaphthalene), the beta-isomer is more tenacious, more pleasant, and more stable under formulation stress (e.g., in soap). It has no known natural occurrence and is synthesized via Friedel–Crafts acylation of naphthalene with acetyl chloride in the presence of aluminum chloride.
Olfactory Profile & Perfumery Applications
Olfactory family: Powdery, floral, fruity-floral
Functional Role: Floral booster, base note modifier, terminal fixative
Primary perfumery uses:
White florals: Neroli, Orange blossom, Jasmine
Exotic florals: Magnolia, Frangipani, Sweet Pea, Honeysuckle, Narcissus
Base layering: With salicylates, indoles, coumarin, and fruity esters
Drydown modifier: Adds powdery sweetness and long-lasting floral warmth
Recommended levels in fragrance concentrate:
Trace to 1% (higher in floral bases and honeysuckle types)
Stable in soap, suitable for use in functional products
Industrial and Flavor Applications
Methyl Naphtyl Ketone Beta is approved for flavor use and holds FEMA GRAS status (2690) and is FDA-approved (21 CFR 121.1164).
Used in flavorings such as:
Strawberry
Grape
Citrus compounds
Neroli
Imitation fruit and vanilla blends
Typical usage:
0.5–5 ppm in beverages or desserts
Up to 700 ppm in chewing gum (for flavor retention)
Regulatory & Safety Overview
IFRA Compliance: Not currently restricted
EU Cosmetics Regulation (Annex III): Not a listed allergen
FEMA: GRAS 2690
ECHA: Not classified as hazardous under normal conditions
Toxicological summary:
Oral LD₅₀ (rats): 599 mg/kg (Bär & Griepentrog, 1967)
12-week NOEL: 34.2 mg/kg
Irritation: Mild skin irritation possible (1 in 24 subjects, full strength)
Sensitization: Negative in human maximization tests at 2% concentration
Additional Information
Production: Via Friedel–Crafts reaction (Naphthalene + Acetyl chloride + AlCl₃)
Natural occurrence: Not found in nature
Solubility: Good alcohol solubility; stable in mildly alkaline environments
Crystalline Form: Enables precise handling and incorporation into bases
Historically used in both fine fragrance and functional perfumery, beta-Methyl Naphtyl Ketone remains relevant due to its cost-efficiency, stability, and compatibility with a wide range of floral, fruity, and powdery notes. While it may be less fashionable than contemporary floral bases, its impact in classic honeysuckle, orange blossom, and wisteria accords remains irreplaceable.
Sources
Perfume and Flavor Materials of Natural Origin – S. Arctander (1961)
FEMA GRAS Database (2690)
NCBI PubChem Compound Summary for CID 7122
Bär & Griepentrog, 1967 – Toxicology Reports
Fulvio Ciccolo – Scentspiracy Internal Archive (2022)