The Enantiopure N-Protected Amino Ester Building Block for Peptide Synthesis, Asymmetric Synthesis, and Medicinal Chemistry: BOC-L-Valine Methyl Ester (CAS# 58561-04-9)

BOC-L-Valine methyl ester (CAS# 58561-04-9), also known as N-(tert-butoxycarbonyl)-L-valine methyl ester, Boc-Val-OMe, N-Boc-L-valine methyl ester, or (S)-methyl 2-((tert-butoxycarbonyl)amino)-3-methylbutanoate, is a protected amino acid derivative with the molecular formula C₁₁H₂₁NO₄ and a molecular weight of 231.29 g/mol. Its molecular structure features an L-valine backbone with a tert-butoxycarbonyl (Boc) protecting group on the α-amino functionality and a methyl ester at the carboxyl terminus. The L-stereochemistry at the α-carbon (S-configuration) confers chirality that is essential for its applications in asymmetric synthesis and peptide coupling.

As a colorless to light yellow to light orange clear liquid with a boiling point of 194°C, a density of 1.004 g/mL at 25°C, and a refractive index of n20/D 1.44, the compound exhibits a specific rotation of [α]²⁰/D −22° (c = 1 in methanol). It is stable when stored in a dark place, sealed in dry conditions at room temperature, and should be handled under inert gas to avoid moisture.

BOC-L-Valine methyl ester is a fundamental building block in modern peptide chemistry and organic synthesis. Its orthogonal protecting group strategy—the Boc group (cleaved under acidic conditions) and the methyl ester (cleaved under basic conditions or converted to the acid)—enables controlled chemoselectivity in stepwise peptide assembly. The valine isopropyl side chain provides hydrophobic, sterically moderate character that is widely used in sequences requiring valine-like steric and conformational behavior. Based on its chemical characteristics and industrial significance, this article systematically analyzes the key properties, core application areas, global market structure, regulatory landscape, and future outlook of this strategically important chiral building block.

Core Application Fields and Demand

Market demand for BOC-L-Valine methyl ester (CAS# 58561-04-9) is concentrated in three primary sectors: peptide synthesis and peptidomimetic development (approximately 50–55% of global consumption), asymmetric synthesis and chiral auxiliary preparation (approximately 25–30%), and medicinal chemistry and pharmaceutical intermediate manufacturing (approximately 15–20%). Its enantiopure L-configuration and orthogonal protecting group strategy serve as the core drivers of sustained demand growth.

In peptide synthesis and peptidomimetic development, BOC-L-valine methyl ester is a specialized reagent commonly utilized in stepwise peptide synthesis workflows. The Boc-protected amino group and methyl ester on the carboxylate provide stable, masked functionality that supports controlled coupling during segment assembly and downstream transformations to carboxylic acid or activated derivatives. The compound is used as a protected intermediate for segment condensation strategies, where a valine unit is incorporated into a growing peptide fragment under conditions compatible with Boc protection. The methyl ester functionality serves as a temporary carboxylate mask that can improve solubility and facilitate purification at the intermediate stage, before further conversion to the corresponding acid or activated coupling partner. Custom peptide manufacturers and academic peptide chemistry labs often select this derivative to introduce a single valine residue in a protected form that can be carried through iterative synthesis steps. The hydrophobic valine side chain contributes the characteristic hydrophobicity associated with many peptide motifs, making this ester form a practical choice for library synthesis and sequence optimization studies. In peptidomimetic and SAR (structure-activity relationship) studies, BOC-L-valine methyl ester serves in medicinal chemistry and chemical biology programs that prepare peptidomimetic scaffolds and valine-containing bioactive molecules.

In asymmetric synthesis and chiral auxiliary preparation, BOC-L-valine methyl ester is used as a chiral auxiliary for the asymmetric synthesis of oxazolidinones and other chiral compounds. The compound delivers >99% enantiomeric excess in multigram synthesis of chiral auxiliaries with yields >50%. The L-configuration guarantees correct stereochemical outcomes in asymmetric synthesis and diastereomer preparation. The orthogonal Boc group enables selective acid-labile deprotection, while the methyl ester ensures efficient C-terminal activation. Substituting Boc-L-Val-OMe with incorrect protecting group or enantiomer analogs causes stereochemical erosion and route incompatibility, making the optically pure N-Boc-L-valine methyl ester essential for reliable synthetic outcomes. The compound is also used to produce β-amino acids, which are important in the biosynthesis of proteins.

In pharmaceutical intermediate manufacturing, BOC-L-valine methyl ester is widely used as an intermediate in organic synthesis and pharmaceutical applications. It is particularly useful in the preparation of bioactive molecules and in solution-phase peptide synthesis. Amino acids and amino acid derivatives have been commercially used as ergogenic supplements, influencing the secretion of anabolic hormones and preventing exercise-induced muscle damage.

In organic synthesis and research, BOC-L-valine methyl ester is commonly used in scientific research, particularly in the field of peptide chemistry, where it serves as a building block. It is utilized in fluorous solid-phase extraction and as a versatile intermediate in various chemical reactions.

Major Market Participants

The global supply system for BOC-L-Valine methyl ester (CAS# 58561-04-9) features a pattern of “specialized peptide synthesis suppliers, multinational chemical distributors, and Chinese manufacturers serving distinct market segments.” As a specialized chiral building block rather than a bulk commodity, the market is characterized by a moderate number of suppliers catering to pharmaceutical R&D, peptide synthesis, and academic research.

In the global research and high-purity segment, key international suppliers include Tokyo Chemical Industry (TCI), offering the compound at >95.0% purity (T)(HPLC) with product code B6020; Sigma-Aldrich (Merck), offering 98% purity; AKSci, offering >98% (GC) purity; and TargetMol, offering research-grade material. Other suppliers include Creative Peptides (cGMP peptide manufacturer), BenchChem, MedChemExpress, and various research chemical distributors serving the pharmaceutical and biotechnology communities. These suppliers serve the pharmaceutical, biotechnology, and academic research communities with products that meet rigorous quality specifications, typically at 95–98% purity.

In the industrial and large-scale production segment, Chinese manufacturers have emerged as significant players in the global supply chain. XinChem is a reliable manufacturer and supplier of high-purity BOC-L-Valine methyl ester from China. Chinese suppliers offer the compound at various purity grades (typically 95% to 98%) and packaging sizes ranging from grams to kilograms, serving both domestic and export markets with competitive pricing. Other Chinese suppliers include Ningbo Inno Pharmchem Co., Ltd., which offers competitive pricing and excellent customer service, as well as various specialized fine chemical manufacturers.

Regional Market Dynamics

The global BOC-L-Valine methyl ester market exhibits distinct regional characteristics, with production concentrated in Asia-Pacific (particularly China) and consumption distributed across North America, Europe, and the Asia-Pacific region, aligned with the pharmaceutical, biotechnology, and academic research industries in these regions. Global and regional market trends from 2019-2024 and forecasts to 2029 indicate steady growth for this compound.

The Asia-Pacific region has emerged as a significant production hub for BOC-L-Valine methyl ester, with China hosting numerous manufacturers and suppliers including XinChem. The region’s competitive advantages include lower production costs, established chemical infrastructure, and proximity to rapidly growing pharmaceutical and peptide synthesis industries. Chinese suppliers offer the compound at various purity grades and packaging options, serving both domestic and export markets. The growing pharmaceutical R&D, peptide synthesis, and biotechnology sectors in China, Japan, South Korea, and Southeast Asia continue to drive regional consumption growth.

North America remains a key market for high-purity and research-grade BOC-L-Valine methyl ester, driven by demand from the pharmaceutical industry, biotechnology companies, CROs, and academic research institutions. The United States hosts numerous research organizations, pharmaceutical companies, and contract research organizations that require high-quality chiral building blocks for drug discovery, peptide synthesis, and medicinal chemistry. Suppliers such as AKSci maintain stock and ship products from the USA. The region’s well-established regulatory framework and emphasis on product quality support demand for high-grade research chemicals and pharmaceutical intermediates.

Europe is characterized by stringent regulatory requirements and a strong focus on quality and sustainability in pharmaceutical and chemical research. European pharmaceutical companies, peptide synthesis laboratories, and research institutions demand high-purity chiral building blocks with comprehensive documentation. TCI and other distributors serve the European market with in-stock availability.

Japan represents a specialized market where BOC-L-Valine methyl ester is supplied by TCI Chemicals and other distributors for pharmaceutical research, peptide synthesis, and fine chemical applications.

Regulatory and Safety Considerations

As a research chemical, pharmaceutical intermediate, and peptide synthesis building block, BOC-L-Valine methyl ester (CAS# 58561-04-9) is subject to regulatory oversight in major global economies. Compliance with relevant regulations is essential for market access and trade.

GHS classification and handling: BOC-L-Valine methyl ester is classified with the signal word “Warning”. Hazard statements include H315 (Causes skin irritation), H319 (Causes serious eye irritation), and H335 (May cause respiratory irritation). Precautionary statements include P261 (Avoid breathing dust/fume/gas/mist/vapors/spray), P264 (Wash skin thoroughly after handling), P271 (Use only outdoors or in a well-ventilated area), P280 (Wear protective gloves/eye protection/face protection), P302+P352 (IF ON SKIN: Wash with plenty of soap and water), P304+P340 (IF INHALED: Remove person to fresh air and keep comfortable for breathing), P305+P351+P338 (IF IN EYES: Rinse cautiously with water for several minutes; remove contact lenses if present and easy to do; continue rinsing), and P405 (Store locked up). The WGK Germany classification is 3 (high hazard to water). The compound should be stored in a dark place, sealed in dry conditions at room temperature, under inert gas to avoid moisture. Personal protective equipment including lab gloves, safety glasses, or face shields should be worn during handling, and good ventilation conditions should be maintained. The compound is classified as a combustible liquid (storage class 10).

Transport information: BOC-L-Valine methyl ester requires proper packaging, labeling, and documentation for international shipping in compliance with the International Maritime Dangerous Goods Code (IMDG Code) and other transport regulations. The HS code is 2924.19.8000. TCI lists the HS code as 2924.19-000 for export purposes. The compound should be stored under inert gas and protected from moisture, as it is sensitive to decomposition upon exposure to moisture.

Regulatory compliance: In the European Union, the compound must comply with REACH registration requirements and CLP classification under Regulation (EC) No 1272/2008 for import and use. Manufacturers and suppliers must provide comprehensive Safety Data Sheets (SDS) and maintain appropriate documentation. In the United States, BOC-L-Valine methyl ester is intended for research and development use only and is not intended for therapeutic, food, cosmetic, or consumer applications unless explicitly stated otherwise. For pharmaceutical intermediate applications, manufacturers must comply with relevant FDA regulations and quality standards.

Future Outlook

The market outlook for BOC-L-Valine methyl ester is positive, supported by several key growth drivers across its major application segments. While the compound remains a relatively specialized chiral building block, its essential role in peptide synthesis, asymmetric synthesis, and medicinal chemistry positions it for steady growth in the coming years.

Key growth drivers include:

1. Expansion of the peptide therapeutics market: The rapidly growing global market for peptide drugs—with the peptide therapeutics market projected to exceed USD 50 billion by 2030—drives demand for high-quality N-protected amino acid building blocks, including BOC-L-Valine methyl ester.
2. Growth in peptide synthesis and CRO services: Increasing outsourcing of peptide synthesis to contract research organizations (CROs) and custom peptide manufacturers drives demand for reliable, high-purity protected amino acid building blocks.
3. Expansion of asymmetric synthesis in pharmaceutical development: The growing emphasis on stereochemically pure pharmaceutical compounds drives demand for enantiopure chiral building blocks and auxiliaries, such as BOC-L-Valine methyl ester, which delivers >99% ee in multigram synthesis.
4. Increasing focus on peptidomimetic drug discovery: The development of peptidomimetic scaffolds and valine-containing bioactive molecules in medicinal chemistry and chemical biology programs supports demand for versatile protected amino acid building blocks.
5. Growth in solution-phase peptide synthesis: The compound’s methyl ester functionality improves solubility and facilitates purification, making it valuable for solution-phase peptide synthesis workflows.

Challenges and considerations:

• Regulatory compliance: Increasingly stringent pharmaceutical and chemical regulations may require ongoing investment in quality systems and documentation.
• Competition from alternative protecting groups: The market faces competition from other protected amino acid derivatives, including Fmoc-protected analogs.
• Limited scale: As a relatively specialized compound, the market for BOC-L-Valine methyl ester is smaller than that of commodity chemicals.
• Stereochemical purity requirements: The specific requirement for the L-enantiomer (not the racemic mixture or D-enantiomer) necessitates rigorous quality control and enantiomeric purity assurance.
• Moisture sensitivity: The compound requires storage under inert gas and protection from moisture, which may increase handling and storage costs.

To succeed in this evolving market landscape, suppliers must focus on product quality (particularly enantiomeric purity, chemical purity, and batch-to-batch consistency), supply chain reliability, regulatory compliance, and responsive customer service. Companies that can offer high-purity products with comprehensive Certificates of Analysis (COA) confirming enantiomeric excess, flexible packaging options, and technical support for peptide synthesis and pharmaceutical applications will be well-positioned to capture growing demand.

Shanghai XinChem Co., Ltd. (XinChem)

As a world-leading supplier of organic chemicals and chiral building blocks, Shanghai XinChem Co., Ltd. (XinChem) is dedicated to meeting the innovative needs of the pharmaceutical, biotechnology, peptide synthesis, and fine chemical industries. Leveraging extensive experience and advanced manufacturing capabilities, XinChem provides high-quality BOC-L-Valine Methyl Ester (CAS# 58561-04-9) 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 research institutions, pharmaceutical companies, and peptide synthesis laboratories seeking this versatile enantiopure N-protected amino ester 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 BOC-L-Valine methyl ester products. The production process incorporates established synthetic routes—including the protection of L-valine methyl ester using di-tert-butyl dicarbonate (Boc₂O) under controlled conditions—enabling the delivery of products with purity ≥98% (GC/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 peptide synthesis, asymmetric synthesis, and medicinal chemistry applications.

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 (GC/HPLC), specific optical rotation, and impurity profiles. This commitment to quality ensures that XinChem’s BOC-L-Valine methyl ester meets the stringent requirements of pharmaceutical R&D, peptide synthesis, and research applications.

2. Product Advantages

High Purity and Consistent Quality
XinChem offers BOC-L-Valine methyl ester with purity ≥98% (GC/HPLC), ensuring optimal performance in peptide synthesis, asymmetric synthesis, and pharmaceutical applications. The product’s high purity minimizes the risk of unwanted side reactions and impurities, making it suitable for demanding applications in drug discovery, peptide therapeutics, and fine chemical synthesis.

Comprehensive Specifications
Key specifications include:

• Molecular Formula: C₁₁H₂₁NO₄
• Molecular Weight: 231.29 g/mol
• CAS Number: 58561-04-9
• Synonyms: N-(tert-Butoxycarbonyl)-L-valine methyl ester; Boc-Val-OMe; N-Boc-L-valine methyl ester; (S)-methyl 2-((tert-butoxycarbonyl)amino)-3-methylbutanoate
• MDL Number: MFCD00672510
• Appearance: Colorless to light yellow to light orange clear liquid
• Purity: ≥98% (GC/HPLC)
• Specific Optical Rotation: [α]²⁰/D −22° (c = 1 in methanol) / +11.0 to +15.0 deg (c=1, CHCl₃)
• Density: 1.004 g/mL at 25°C
• Boiling Point: 194°C
• Refractive Index: n20/D 1.44
• Storage: Keep in dark place, sealed in dry conditions, room temperature; under inert gas, protect from moisture

Flexible Packaging Solutions
XinChem provides a range of packaging options to accommodate diverse customer needs, from laboratory-scale quantities (grams) to industrial-scale packaging (kilograms) and bulk shipments. Customized packaging solutions are available upon request, ensuring safe handling, storage, and transportation.

3. Application Fields

As a versatile enantiopure N-protected amino ester building block, BOC-L-Valine Methyl Ester (CAS# 58561-04-9) exhibits wide application value across multiple industries:

Peptide Synthesis and Peptidomimetic Development:

• Protected building block for stepwise peptide synthesis
• Protected intermediate for segment condensation strategies
• Precursor for valine-containing peptide segments
• Building block for peptidomimetic scaffolds and SAR studies
• Temporary carboxylate mask for improved solubility and purification

Asymmetric Synthesis and Chiral Auxiliary Preparation:

• Chiral auxiliary for asymmetric synthesis of oxazolidinones
• Precursor for β-amino acids
• Enables >99% ee in multigram chiral auxiliary synthesis
• Orthogonal protecting group strategy for selective deprotection and activation

Medicinal Chemistry and Pharmaceutical Intermediates:

• Intermediate in organic synthesis and pharmaceutical applications
• Building block for bioactive molecules
• Precursor for amino acid derivatives and ergogenic supplements

Organic Synthesis and Research:

• Building block for peptide chemistry research
• Reagent for fluorous solid-phase extraction
• Versatile intermediate for various chemical reactions

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 peptide synthesis protocols, guidance on deprotection strategies, 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 handling for moisture-sensitive compounds and proper temperature control.

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 REACH, TSCA, and other regional regulations, helping customers navigate the complexities of global trade.

5. Reasons to Choose XinChem

• Professionalism: Extensive experience and deep expertise in chiral building block synthesis and supply since 2005.
• Quality: Rigorous quality control, high purity (≥98%), 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 including COA confirming enantiomeric purity.

Contact us today to start your partnership with XinChem!

Website: www.xinchem.com

Email: sales1@xinchem.com

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