The Essential Precursor and Reference Standard for [¹⁸F]FET PET Brain Tumor Imaging and Neurological Drug Discovery: L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate (CAS# 854750-33-7)

L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate (CAS# 854750-33-7), also known as O-(2-fluoroethyl)-L-tyrosine trifluoroacetate, FET trifluoroacetate, or L-FET TFA, is a fluorinated chiral amino acid derivative with the molecular formula C₁₁H₁₄FNO₃·C₂HF₃O₂ and a molecular weight of 341.26 g/mol. Its molecular structure consists of an L-tyrosine backbone bearing a 2-fluoroethoxy substituent at the para-hydroxyl position of the aromatic ring, presented as the trifluoroacetate salt. This strategic fluorine incorporation—combining the D-amino acid backbone’s metabolic stability with the fluoroethoxy side chain’s radiolabeling capability—confers exceptional utility in positron emission tomography (PET) imaging and neurological research.

As a white to off-white crystalline powder, the compound is soluble in water and polar organic solvents, with a purity of ≥97% (HPLC) typically available. It should be stored at −20°C in a dry, dark place under sealed conditions. The trifluoroacetate salt form provides enhanced water solubility and stability compared to the free base, facilitating its use in radiopharmaceutical precursor synthesis and analytical applications. This compound serves as the indispensable non-radioactive reference standard and precursor backbone for the radiosynthesis of O-(2-[¹⁸F]fluoroethyl)-L-tyrosine ([¹⁸F]FET), a leading amino acid PET tracer for brain tumor diagnostics and neurological research. Based on its chemical characteristics and biomedical significance, this article systematically analyzes the key properties, core application areas, global market structure, regulatory landscape, and future outlook of this strategically important fluorinated amino acid derivative.

Core Application Fields and Demand

Market demand for L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate (CAS# 854750-33-7) is concentrated in three primary sectors: PET radiopharmaceutical precursor synthesis and reference standards (approximately 55–60% of global consumption), neurological drug discovery and brain tumor research (approximately 25–30%), and pharmaceutical quality control and analytical method validation (approximately 10–15%). Its unique combination of the L-tyrosine scaffold, fluoroethoxy substituent, and trifluoroacetate salt form serves as the core driver of sustained demand growth.

In PET radiopharmaceutical precursor synthesis, this compound is the essential non-radioactive reference standard and precursor backbone for the radiosynthesis of O-(2-[¹⁸F]fluoroethyl)-L-tyrosine ([¹⁸F]FET). [¹⁸F]FET is a well-established amino acid PET tracer that has demonstrated exceptional diagnostic potential in brain tumor imaging over the past two decades. The tracer is actively transported into the brain and cancer cells by L-type amino acid transporters (LAT1/LAT2), which are overexpressed in gliomas and other brain tumors, providing high-contrast visualization of tumor tissue with minimal background uptake in normal brain parenchyma. Unlike the widely absorbed [¹⁸F]FDG in both tumor and normal brain tissues, [¹⁸F]FET demonstrates specific uptake only in tumor tissue while showing almost negligible uptake in normal brain tissue, enabling accurate delineation of infiltrating tumors and the differentiation of brain tumors from inflammatory lesions. The synthesis of [¹⁸F]FET typically involves a two-step procedure: ¹⁸F-fluoroethylation of a protected L-tyrosine precursor followed by deprotection, or direct nucleophilic radiofluorination using a tosylate-protected precursor. Fully automated one-pot radiosynthesis methods have been developed using the GE TracerLab FXFN synthesis module, achieving 35±5% (n=22) yield non-decay-corrected (55±5% decay-corrected) with radiochemical and enantiomeric purity of >99% and specific activity of >90 GBq/μmol after 63 minutes of radiosynthesis including HPLC purification. The trifluoroacetate salt form of this compound serves as the cold (non-radioactive) reference standard essential for quality control and analytical method validation, ensuring the chemical and radiochemical purity of the final [¹⁸F]FET product. Reference standards for [¹⁸F]FET hydrochloride are commercially available from specialized radiochemical companies, with the free base form serving as the foundational reference material.

In neurological drug discovery and brain tumor research, this compound shows remarkable application prospects. Current research suggests that it may play a key role in the treatment of neurological disorders. For Alzheimer’s disease, it may play a role in delaying the cognitive decline of patients by interfering in nerve signaling pathways and regulating information exchange between neurons, bringing new hope for protecting patients’ memory and thinking ability. In the study of brain injury repair, it is expected to stimulate the self-repair mechanism of damaged nerve tissue, accelerate the regeneration and functional reconstruction of nerve cells, and help patients restore normal brain function. The compound serves as a valuable research tool for investigating amino acid transport mechanisms, studying the structure-activity relationships of fluorinated amino acid derivatives, and developing novel therapeutic agents targeting neurotransmitter systems. Recent research has focused on enhancing the tumor-to-background ratio (TBR) of [¹⁸F]FET in brain tumor imaging by substituting deuterium for hydrogen, with novel PET radiotracer [¹⁸F]d4-FET successfully synthesized to improve diagnostic sensitivity and accuracy for glioma imaging.

In pharmaceutical quality control and analytical method validation, this compound is utilized as a reference standard for the identification and quantification of related substances in pharmaceutical formulations containing fluorinated amino acid derivatives. The compound’s well-characterized structure and high purity make it suitable for use in analytical method development, validation, and quality control in the radiopharmaceutical industry. It serves as the indispensable analytical reference standard for [¹⁸F]FET production, ensuring batch-to-batch consistency and regulatory compliance.

Key Properties and Reactivity Profile

L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate (CAS# 854750-33-7) is a fluorinated chiral amino acid derivative whose value derives from its well-defined structure and analytical characteristics.

Key physicochemical parameters include:

• Molecular Formula: C₁₁H₁₄FNO₃·C₂HF₃O₂
• Molecular Weight: 341.26 g/mol (trifluoroacetate salt); 227.23 g/mol (free base)
• CAS Number: 854750-33-7
• Synonyms: O-(2-Fluoroethyl)-L-tyrosine trifluoroacetate; FET trifluoroacetate; L-FET TFA
• IUPAC Name: (2S)-2-amino-3-[4-(2-fluoroethoxy)phenyl]propanoic acid
• Appearance: White to off-white crystalline powder
• Purity: ≥97% (HPLC)
• Solubility: Soluble in water and polar organic solvents
• Storage: −20°C, dry, dark place, sealed conditions
• SMILES: C1=CC(=CC=C1CC@@HN)OCCF
• InChIKey: QZZYPHBVOQMBAT-JTQLQIEISA-N
• FDA UNII: P6VBV68WPV

The compound’s reactivity is defined by the L-tyrosine amino acid backbone, which enables peptide coupling and derivatization, and the fluoroethoxy substituent, which provides a site for radiolabeling with ¹⁸F. The trifluoroacetate counterion enhances water solubility and facilitates purification. The specific 2-fluoroethoxy substitution at the para position of the aromatic ring is critical for biological activity—the tracer is actively transported into the brain and cancer cells by LAT1 and possibly other amino acid transporters. Substituting the L-configuration with the D-enantiomer or altering the fluoroethoxy position would result in significantly different biological activity and pharmacokinetic properties. The compound functions as a substrate for amino acid transporters in cells, competing with native amino acids for uptake into cells, particularly in tumor tissues where metabolic activity is heightened.

Major Market Participants

The global supply system for L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate (CAS# 854750-33-7) features a pattern of “specialized radiopharmaceutical chemical suppliers, research-grade chemical distributors, and Chinese manufacturers serving distinct market segments.” As a highly specialized chiral building block rather than a commodity chemical, the market is characterized by a limited number of suppliers catering to the radiopharmaceutical, pharmaceutical R&D, and academic research communities.

In the global radiopharmaceutical and high-purity segment, key suppliers include ABX advanced biochemical compounds (Germany), offering FET hydrochloride as a reference standard for [¹⁸F]FET with purity ≥95% and molar mass of 263.69 g/mol for the hydrochloride form. BOC Sciences (USA) offers O-(2-fluoroethyl)tyrosine (CAS 854750-33-7) as a building block with molecular formula C₁₁H₁₄FNO₃ and molecular weight 227.23 g/mol. BenchChem provides the compound as the indispensable analytical reference standard and precursor backbone for [¹⁸F]FET radiosynthesis. EvitaChem offers O-(2-fluoroethyl)tyrosine as a screening compound for non-human research applications. Other suppliers include CymitQuimica, which offers L-Tyrosine, O-(2-fluoroethyl)-, 2,2,2-trifluoroacetate (1:1) with formula C₁₁H₁₄FNO₃·C₂HF₃O₂, and Biozol (Germany), offering the compound under catalog number CMS-F556259.

In the industrial and research-grade segment, Chinese manufacturers have emerged as significant players in the global supply chain. XinChem is a reliable manufacturer and supplier of high-purity L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate from China, offering the compound with stringent quality standards for use in radiopharmaceutical precursor synthesis, neurological research, and pharmaceutical quality control. XinChem provides the compound as a white to off-white crystalline powder with comprehensive quality documentation and flexible packaging options. Other Chinese suppliers include 四川省维克奇生物科技有限公司 (Sichuan Weikeqi Biological Technology), offering the compound at ≥97% purity in 20 mg packaging with storage at −20°C, dry, dark, and sealed conditions, and 南京协诺生物技术有限公司 (Nanjing Xienuo Biotechnology), supplying the compound for research applications.

Regional Market Dynamics

The global L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate market exhibits distinct regional characteristics, with production and distribution spanning Asia-Pacific, North America, and Europe, aligned with the radiopharmaceutical, pharmaceutical, and academic research industries in these regions. The broader tyrosine market was valued at approximately USD 450 million in 2024 and is projected to reach USD 720 million by 2032, growing at a CAGR of 6.2%, with the radiolabeled amino acid segment benefiting from this growth.

The Asia-Pacific region has emerged as a significant production hub for fluorinated amino acid derivatives, with China hosting manufacturers and suppliers including XinChem. The region’s competitive advantages include established chemical infrastructure, cost-effective manufacturing, and proximity to rapidly growing pharmaceutical and biotechnology industries. Chinese suppliers offer the compound at various purity grades (typically ≥97%) and packaging options, serving both domestic and export markets. The growing radiopharmaceutical R&D and nuclear medicine sectors in China, Japan, South Korea, and India continue to drive regional consumption growth. The global L-tyrosine market in China is projected to expand at a compound annual growth rate of 12.3–15.7% from 2025 to 2030, reaching a market size of over RMB 3.8 billion by 2030.

North America remains a key market for high-purity and research-grade L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate, driven by demand from the radiopharmaceutical industry, pharmaceutical companies, and academic research institutions. The United States hosts numerous research organizations, PET tracer manufacturing facilities, and pharmaceutical companies that require high-quality chiral building blocks for drug discovery and radiopharmaceutical development. BOC Sciences, BenchChem, and EvitaChem serve the North American market with extensive distribution networks. The region’s well-established regulatory framework, including FDA oversight and orphan drug designations for brain tumor diagnostics, supports demand for high-grade research chemicals and radiopharmaceutical precursors. The FDA has issued Fast Track, Orphan Drug, and Priority Review designations for floretyrosine F18 (the radiolabeled form), demonstrating regulatory recognition of its clinical value.

Europe is characterized by stringent regulatory requirements and a strong focus on quality in radiopharmaceutical and pharmaceutical research. European radiopharmaceutical manufacturers and research institutions demand high-purity chiral building blocks with comprehensive documentation. ABX advanced biochemical compounds (Germany) is a key supplier of reference standards for [¹⁸F]FET, serving the European nuclear medicine community. The region’s advanced nuclear medicine infrastructure and strong academic research base support steady demand for fluorinated amino acid derivatives for PET tracer development and neurological research.

Japan represents a specialized market where the compound is applied in advanced radiopharmaceutical research, brain tumor imaging, and neurological drug discovery programs.

Regulatory and Safety Considerations

As a research chemical, radiopharmaceutical precursor, and pharmaceutical reference standard, L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate (CAS# 854750-33-7) is subject to regulatory oversight in major global economies. Compliance with relevant regulations is essential for market access and trade.

Regulatory compliance: In the United States, the compound has a FDA Unique Ingredient Identifier (UNII) of P6VBV68WPV. The FDA Substance Registration System lists the compound under the preferred substance name O-(2-FLUOROETHYL)TYROSINE with formula C₁₁H₁₄FNO₃. The radiolabeled form, floretyrosine F18, has received Fast Track, Orphan Drug, and Priority Review designations from the FDA, underscoring its clinical significance for brain tumor diagnostics. The compound is not a controlled substance.

In the European Union, the compound must comply with REACH registration requirements for import and use. Manufacturers and suppliers must provide comprehensive Safety Data Sheets (SDS) and maintain appropriate documentation.

GHS classification and handling: The compound is intended for research and development use only and is not intended for therapeutic, food, cosmetic, or consumer applications unless explicitly stated otherwise. Standard laboratory safety practices should be followed during handling, including the use of appropriate personal protective equipment (gloves, protective clothing, and eye/face protection). The compound should be stored at −20°C in a dry, dark place under sealed conditions, protected from moisture and light.

Transport information: L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate is not classified as hazardous material for DOT/IATA transport purposes. Proper packaging, labeling, and documentation are nevertheless required for international shipping. The compound is typically shipped with appropriate temperature control and moisture protection.

Future Outlook

The market outlook for L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate is positive, supported by several key growth drivers across its major application segments. While the compound remains a relatively specialized fluorinated amino acid derivative, its essential role in [¹⁸F]FET PET tracer development and neurological research positions it for steady growth in the coming years. The global tyrosine market—which includes this compound as a high-value derivative—is projected to grow from USD 450 million in 2024 to USD 720 million by 2032 at a CAGR of 6.2%.

Key growth drivers include:

1. Expansion of the PET imaging market: The growing global demand for PET imaging in oncology, neurology, and cardiology drives demand for high-quality PET tracers and their precursors, including [¹⁸F]FET and its reference standards. The clinical evaluation of [¹⁸F]FET has demonstrated accurate delineation of infiltrating tumors and differentiation of brain tumors from inflammatory lesions, supporting its adoption in routine clinical practice.
2. Growth in brain tumor diagnostics: The increasing incidence of brain tumors and the need for non-invasive diagnostic tools support continued demand for [¹⁸F]FET PET imaging. The tracer’s ability to demonstrate specific uptake only in tumor tissue while showing almost negligible uptake in normal brain tissue makes it superior to [¹⁸F]FDG for brain tumor imaging.
3. Neurological drug discovery: Ongoing research into Alzheimer’s disease, brain injury repair, and other neurological disorders drives demand for fluorinated amino acid derivatives as research tools and potential therapeutic candidates. The compound’s potential role in delaying cognitive decline and stimulating nerve tissue self-repair mechanisms positions it at the forefront of neurological research.
4. Expansion of radiopharmaceutical R&D: Increasing investment in the development of novel radiopharmaceuticals and PET tracers supports demand for high-quality chiral building blocks and reference standards. The development of deuterated analogs such as [¹⁸F]d4-FET demonstrates ongoing innovation in this field.
5. Growth in pharmaceutical quality control: The increasing stringency of pharmaceutical quality control requirements drives demand for well-characterized impurity reference standards and analytical reference materials.

Challenges and considerations:

• Regulatory compliance: Increasingly stringent pharmaceutical and radiopharmaceutical regulations may require ongoing investment in quality systems and documentation.
• Limited scale: As a highly specialized compound, the market for L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate is smaller than that of commodity chemicals, which may limit investment in large-scale production capacity.
• Competition from alternative tracers: The market faces competition from other PET tracers and imaging modalities for brain tumor diagnosis, including [¹¹C]methionine and [¹⁸F]FDG.
• Technical complexity: The synthesis and handling of fluorinated amino acid derivatives require specialized expertise and equipment, creating barriers to entry.
• Cold chain requirements: The compound requires storage at −20°C, which may increase handling and logistics costs.

To succeed in this evolving market landscape, suppliers must focus on product quality (particularly enantiomeric purity and batch-to-batch consistency), supply chain reliability, regulatory compliance, and responsive customer service. Companies that can offer high-purity products, flexible packaging options, and technical support for radiopharmaceutical and neurological research applications will be well-positioned to capture growing demand.

Shanghai XinChem Co., Ltd. (XinChem)

As a world-leading supplier of organic chemicals and pharmaceutical intermediates, Shanghai XinChem Co., Ltd. (XinChem) is dedicated to meeting the innovative needs of the radiopharmaceutical, pharmaceutical, biotechnology, and fine chemical industries. Leveraging extensive experience and advanced manufacturing capabilities, XinChem provides high-quality L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate (CAS# 854750-33-7) to customers worldwide. As a trusted manufacturer and supplier based in China, XinChem combines competitive pricing, reliable supply, and exceptional service to establish itself as a preferred partner for businesses and research institutions seeking this essential fluorinated chiral building block.

1. Technical Advantages

Advanced Synthesis and Purification Processes
XinChem utilizes state-of-the-art manufacturing facilities and rigorous quality control measures to ensure the purity, consistency, and safety of its L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate products. The production process incorporates advanced synthetic technologies—including chiral synthesis, fluoroethylation, and trifluoroacetate salt formation—enabling the delivery of products with purity ≥97% (HPLC) to meet diverse application requirements. Strict process control ensures consistent enantiomeric purity (L-configuration), minimal impurities, and batch-to-batch reproducibility, providing customers with reliable performance in radiopharmaceutical precursor synthesis, neurological research, and pharmaceutical quality control.

Full-Chain Quality Control
The production process strictly adheres to international quality standards, with comprehensive quality control covering raw material sourcing, in-process monitoring, and finished product testing. Each batch is accompanied by a detailed Certificate of Analysis (COA) documenting physical and chemical properties, purity data (HPLC), optical rotation, and impurity profiles. This commitment to quality ensures that XinChem’s L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate meets the stringent requirements of radiopharmaceutical, pharmaceutical, and research applications.

2. Product Advantages

High Purity and Consistent Quality
XinChem offers L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate with purity ≥97% (HPLC), ensuring optimal performance in PET tracer synthesis, neurological research, and pharmaceutical quality control applications. The product’s high purity minimizes the risk of unwanted side reactions and impurities, making it suitable for demanding applications in radiopharmaceutical precursor synthesis and analytical reference standards.

Comprehensive Specifications
Key specifications include:

• Molecular Formula: C₁₁H₁₄FNO₃·C₂HF₃O₂
• Molecular Weight: 341.26 g/mol (trifluoroacetate salt); 227.23 g/mol (free base)
• CAS Number: 854750-33-7
• Synonyms: O-(2-Fluoroethyl)-L-tyrosine trifluoroacetate; FET trifluoroacetate; L-FET TFA
• IUPAC Name: (2S)-2-amino-3-[4-(2-fluoroethoxy)phenyl]propanoic acid
• Appearance: White to off-white crystalline powder
• Purity: ≥97% (HPLC)
• Solubility: Soluble in water and polar organic solvents
• Storage: −20°C, dry, dark place, sealed conditions
• FDA UNII: P6VBV68WPV

Flexible Packaging Solutions
XinChem provides a range of packaging options to accommodate diverse customer needs, from laboratory-scale quantities (10 mg, 20 mg, 50 mg, 100 mg) to industrial-scale packaging (500 mg, 1 g, 5 g) and bulk shipments. Customized packaging solutions are available upon request, ensuring safe handling, storage, and transportation with appropriate temperature control and moisture protection.

3. Application Fields

As a versatile fluorinated chiral building block, L-Tyrosine, O-(2-fluoroethyl)-, trifluoroacetate (CAS# 854750-33-7) exhibits wide application value across multiple industries:

PET Radiopharmaceuticals:

• Non-radioactive reference standard for O-(2-[¹⁸F]fluoroethyl)-L-tyrosine ([¹⁸F]FET)
• Precursor backbone for the radiosynthesis of [¹⁸F]FET
• Quality control reference material for PET tracer manufacturing
• Analytical standard for method development and validation

Neurological Research:

• Research tool for studying amino acid transport mechanisms (LAT1/LAT2)
• Investigation of nerve signaling pathways in Alzheimer’s disease
• Study of brain injury repair mechanisms and nerve cell regeneration
• Tool for investigating the structure-activity relationships of fluorinated amino acids

Pharmaceutical Research:

• Building block for drug discovery programs targeting neurological disorders
• Reference standard for pharmaceutical impurity identification and quantification
• Reagent for studying the metabolic stability of fluorinated amino acid derivatives

Analytical Chemistry:

• Reference standard for HPLC and LC-MS method development
• Quality control material for radiopharmaceutical production

4. Service Support

Technical Expertise and Customized Solutions
XinChem’s team of experienced chemists and pharmaceutical scientists provides full technical support throughout the customer journey—from product selection and specification development to application guidance and troubleshooting. Whether customers require optimization of radiopharmaceutical synthesis parameters, guidance on handling and storage, or assistance with regulatory documentation, XinChem’s technical experts are ready to help. Custom synthesis and contract manufacturing with flexible scaling from R&D to commercial quantities are available upon request.

Global Logistics and Reliable Supply
With established supply chains serving markets across Europe, North America, Asia-Pacific, and beyond, XinChem ensures timely delivery and consistent product availability. The company’s logistics team manages all aspects of international shipping, including customs clearance and documentation, with appropriate temperature control (−20°C) and moisture protection for product stability.

Regulatory Support
XinChem provides comprehensive documentation to support regulatory compliance, including Safety Data Sheets (SDS), Certificates of Analysis (COA), and other required certificates. The company stays current with evolving regulatory requirements in major markets, including FDA, EMA, REACH, and other regional regulations, helping customers navigate the complexities of global trade.

5. Reasons to Choose XinChem

• Professionalism: Extensive experience and deep expertise in fluorinated chiral compound synthesis and supply.
• Quality: Rigorous quality control, high purity (≥97%), and adherence to international standards.
• Reliability: Stable supply, competitive pricing, and timely delivery.
• Flexibility: Customized solutions to meet diverse customer needs, including custom synthesis and packaging.
• Service: Responsive technical support and comprehensive documentation.

Contact us today to start your partnership with XinChem!

Website: www.xinchem.com

Email: sales1@xinchem.com

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