FlavScents AInsights Entry for 2-Isobutyl Thiazole (CAS: 18640-74-9)

1. Identity & Chemical Information

2-Isobutyl thiazole is a chemical compound commonly used in flavor and fragrance applications. Its IUPAC name is 2-(2-methylpropyl)-1,3-thiazole. The CAS number for this compound is 18640-74-9. It is identified by FEMA number 2208. The molecular formula is C7H11NS, and it has a molecular weight of 141.23 g/mol. The compound features a thiazole ring, which is crucial for its characteristic odor profile. The presence of the isobutyl group contributes to its distinct green, earthy aroma, often associated with bell peppers.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

2-Isobutyl thiazole is known for its potent green, earthy, and slightly nutty aroma, reminiscent of raw green bell peppers. It is often described as having a moderate to high intensity with a sharp, fresh character. The compound is primarily used as an impact note in flavor formulations, providing a realistic green pepper note. The odor threshold is relatively low, making it effective even at minimal concentrations.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

2-Isobutyl thiazole naturally occurs in green bell peppers and is also found in other vegetables such as tomatoes and peas. It is formed through the Maillard reaction, a chemical reaction between amino acids and reducing sugars that occurs during the cooking process. This compound is significant for natural flavor designations due to its presence in various natural sources.

Citation hooks: FlavScents; food chemistry literature; EFSA/JECFA monographs

4. Use in Flavors

In flavor applications, 2-isobutyl thiazole is used to impart a green, fresh note to a variety of products, including sauces, soups, and savory snacks. It serves as an impact note, enhancing the authenticity of vegetable flavors. Typical use levels in finished food products range from 0.1 to 5 ppm, with higher concentrations used in more robust flavor profiles. The compound is stable under typical processing conditions but may degrade under extreme heat or acidic environments.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In the fragrance industry, 2-isobutyl thiazole is utilized in green and herbal fragrance families. It acts as a modifier, adding freshness and realism to compositions. The compound is typically used in trace amounts due to its high potency, contributing primarily to the top notes of a fragrance. Its volatility allows it to provide an immediate impact upon application.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

In the United States, 2-isobutyl thiazole is recognized as GRAS (Generally Recognized As Safe) by FEMA for flavor use. In the European Union, it is regulated under Regulation (EC) No 1334/2008 and has an assigned FL number. The United Kingdom follows similar regulations post-Brexit. In Asia, including Japan and China, and in Latin America, such as Brazil, the compound is generally accepted for use in flavors, although specific regulations may vary.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

For oral exposure, 2-isobutyl thiazole is considered safe at the levels typically used in food products, with no specific ADI established. Dermal exposure in fragrance applications is generally low risk, with no significant irritation or sensitization reported. Inhalation exposure is minimal due to its low volatility in typical use concentrations. The risk profiles for food and fragrance applications are similar, with no significant differences noted.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

2-Isobutyl thiazole is valued for its ability to impart a fresh, green note that enhances the authenticity of vegetable flavors. It synergizes well with other green and herbal notes, but care must be taken to avoid overpowering the formulation due to its high potency. It is often under-used in complex flavor systems where its impact can be masked by other components.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on 2-isobutyl thiazole is well-established, with comprehensive sensory and regulatory information available. Industry practices are well-documented, although specific use levels may vary based on formulation needs. No significant data gaps or regulatory ambiguities are noted.

Citation hooks: FlavScents

QA Check

• All required sections 1–9 are present
• "Citation hooks:" line is present under each section
• Flavor section includes ppm ranges
• Toxicology section covers oral, dermal, inhalation
• Regulatory section mentions US, EU, UK, Asia, Latin America
• If complex natural material: includes section 5a (not applicable here)

About FlavScents AInsights (Disclosure)
FlavScents AInsights integrates information from authoritative government, scientific, academic, and industry sources to provide applied, exposure-aware insight into flavor and fragrance materials. Data are drawn from regulatory bodies, expert safety panels, peer-reviewed literature, public chemical databases, and long-standing professional practice within the flavor and fragrance community. Where explicit published values exist, they are reported directly; where gaps remain, AInsights reflects widely accepted industry-typical practice derived from convergent sensory behavior, historical commercial use, regulatory non-objection, and expert consensus. All such information is clearly labeled to distinguish documented data from professional guidance or informed estimation, with the goal of offering transparent, practical, and scientifically responsible context for researchers, formulators, and regulatory specialists. This section is generated using advanced computational language modeling to synthesize and structure information from established scientific and regulatory knowledge bases, with the intent of supporting—not replacing—expert review and judgment.

Generated 2026-05-20 09:11:19 GMT (p2)