2,2′-(Dithiodimethylene)-difuran (CAS 4437-20-1) — Spicy Top to Middle Note Fragrance Ingredient

Spicy · Sweet

2,2'-(Dithiodimethylene)-difuran

CAS 4437-20-1

Origin
synthetic
Note
Top to Middle
IFRA
Use with awareness
Data as of: Apr 2026

What Is 2,2'-(Dithiodimethylene)-difuran?

2,2′-(Dithiodimethylene)-difuran is a synthetic fragrance ingredient used in advanced perfumery. It creates unique sulfurous notes reminiscent of roasted coffee or toasted bread. People encounter it in niche fragrances where unconventional notes are desired. This ingredient matters because it allows perfumers to create complex, savory accords that stand out in modern compositions.

Safety Profile

USE WITH AWARENESS
Generally safeUse with awarenessProfessional use
Potential skin sensitizer – use caution
Limited safety data available
CAS
4437-20-1
Formula
Mixture
MW
Variable
Odor Family
Spicy · Sweet
Layer 1 · Enthusiast

What Does 2,2'-(Dithiodimethylene)-difuran Smell Like?

2,2′-(Dithiodimethylene)-difuran delivers a powerful, sulfurous character that evolves from an initial burnt matchstick sharpness to a deep, roasted coffee heart. The dry-down reveals surprising gourmand qualities – imagine the crust of freshly baked sourdough meeting dark molasses. Its tenacity allows it to act as both a top note with surprising diffusion and a base note that anchors more volatile materials.

Scent Profile

In Famous Fragrances

Fragrance associations may not reflect actual formulations.

Black Phantom(By Kilian, 2017)

Used to create the dark roasted coffee accord that defines this fragrance, adding depth to the rum and chocolate notes.

Intoxicated(Kerosene, 2015)

Provides the burnt coffee edge that makes this fragrance smell like a Turkish coffee shop at dawn.

Layer 2

2D Molecular Structure

Furan, 2,2'-[dithiobis(methylene)]bis-

SMILES: C(SSCC1=CC=CO1)C1=CC=CO1

Chemistry, Properties & Perfumer Guide

The Chemistry

This sulfur-containing heterocyclic compound belongs to the furan family. The dithiodimethylene bridge creates unique stability while contributing to its distinctive odor profile. Synthesis typically involves the reaction of furfuryl derivatives with sulfur-containing reagents. The compound’s planar structure allows for strong interaction with olfactory receptors, explaining its potent aroma at low concentrations.

Physical & Chemical Properties

Molecular WeightNot publicly available
AppearanceLikely colorless to pale yellow liquid

Perfumer Guide

Note Position
Top to Middle
Volatility
Medium (2-4 hours)
Blending
Challenging
ApplicationTypical %RangeNotes
Fine Fragrance0.1-0.5%Up to 1%Used sparingly for effect
Functional Fragrance0.01-0.1%Up to 0.2%Masking agent for industrial odors

Classic Accords

Tip: Balance with sweet materials to prevent overpowering sulfur character.

Alternatives & Comparisons

1
Furfuryl Mercaptan CAS 98-02-2

When a more intense roasted coffee note is needed, though with greater safety concerns.

2
2-Methyl-3-furanthiol CAS 28588-74-1

For a meatier, more savory sulfur character in gourmand compositions.

Layer 3

Safety, Regulatory & Sustainability

⚠ Regulatory Disclaimer

General reference only. Consult current IFRA Standards Library before formulating.

IFRA Status

Not currently restricted by IFRA, but recommended usage levels should be carefully monitored due to limited safety data.

GHS Classification

H315 Skin irritation H319 Eye irritation

RIFM Assessment

No formal RIFM assessment available. Recommended to follow precautionary principle.

Sustainability

As a synthetic material, production can be controlled to minimize environmental impact. However, sulfur-containing compounds require careful handling to prevent emissions. Future development may focus on more sustainable synthetic pathways.

Explore 2,2'-(Dithiodimethylene)-difuran

Browse essential oils and aroma compounds.

Browse on iHerb →

Affiliate disclosure: we may earn a small commission at no extra cost to you.

References

  1. PubChem Compound Summary CID Not Available
  2. Sulfur Compounds in Fragrance Chemistry

Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.

Report a data error

Ingredient Data Sheet

CAS 4437-20-1

Physical Properties

Molecular Weight226.3 g/mol🔬 PubChem
LogP (Octanol-Water)2.1🔬 PubChem
Boiling Point229 °C🔬 EPA CompTox
log Kp (skin permeability)-2.589💻 Calculated
SMILESC1=COC(=C1)CSSCC2=CC=CO2🔬 PubChem

Volatility & Performance

Fragrance NoteHeart💻 Calculated

Odor & Flavor

Primary Descriptorsroastedsulfurous• leffingwell
Functional Groupsaromatic💻 RDKit
“attractive, caramellic-burnt, "roasted" odor.”📖 Arctander
2,2'-(Dithiodimethylene)-difuran has a powerful, repulsive sulfide odor.📖 Fenaroli

Flavor Notes (Arctander)

“It has found use in the flavor bases which are used to re-constitute the aroma of instant Coffee and other Coffee products. It is also used in imitation Coffee flavor. Another Coffee flavor component, Furfuryl mercaptan, is produced by reduction of the above disulfide.”📖 Arctander

Sensory Thresholds

Odor Detection Threshold0 ppm📖 van Gemert

Regulatory Status

IOFI ClassificationNature Identical📖 Fenaroli
Data Sources & Attribution
Physical data: PubChem (NIH/NLM), U.S. EPA CompTox Dashboard, EPA OPERA models, RDKit. Odor & flavor: Arctander (Perfume & Flavor Chemicals), Fenaroli's Handbook of Flavor Ingredients, Leffingwell. Thresholds: van Gemert (Compilations of Odour Threshold Values). Regulatory: IFRA Standards 51st, FEMA GRAS. Trade names: Surburg (Common Fragrance & Flavor Materials). All data compiled and cross-referenced for perfumertools.com.

Physicochemical Properties

DTXSID: DTXSID3063463

Physical Properties

Molecular Weight 226.31 g/mol🔬 EPA CompTox
Density 1.239 g/cm^3🔬 EPA CTX
Boiling Point 229.5 °C🔬 EPA CTX
Melting Point 10.25 °C🔬 EPA CTX
Flash Point 128.129 °C📊 OPERA
Refractive Index 1.606 Dimensionless📊 OPERA
Molar Volume 176.48 cm^3/mol📊 OPERA

Partition & Solubility

LogP (Octanol-Water) 4.03 Log10 unitless🔬 EPA CTX
LogD (pH 5.5) 3.928 Log10 unitless📊 OPERA
LogD (pH 7.4) 3.923 Log10 unitless📊 OPERA
LogKoa (Octanol-Air) 7.45 Log10 unitless📊 OPERA
Water Solubility 0.015 mol/L📊 OPERA
Henry's Law Constant 0 atm-m3/mole📊 OPERA

Transport Properties

Vapor Pressure 0.001 mmHg📊 OPERA
Surface Tension 48.319 dyn/cm📊 OPERA

Molecular Descriptors

Topological Polar Surface Area 26.28 Ų💻 Computed
H-Bond Donors 0 count💻 Computed
H-Bond Acceptors 4 count💻 Computed
Rotatable Bonds 5 count💻 Computed
Aromatic Rings 2 count💻 Computed
Molar Refractivity 60.883 cm^3/mol📊 OPERA
Polarizability 24.136 Å^3📊 OPERA

Data Sources:

🔬 EPA Experimental data from U.S. EPA CompTox Chemicals Dashboard & CTX APIs. 📊 OPERA Predicted using EPA's OPERA QSAR models. 💻 Computed Calculated from SMILES using RDKit.

Similar Posts