The Essential Chiral Building Block for Solid‑Phase Peptide Synthesis and Targeted Drug Discovery: Boc-L-alanine (CAS 15761-38-3)

Boc‑L‑alanine (Boc‑Ala‑OH, CAS 15761‑38‑3) is a Boc‑protected derivative of the essential natural amino acid L‑alanine, with the molecular formula C₈H₁₅NO₄, molecular weight 189.21 g/mol, and typical white to off‑white crystalline powder appearance. Its structure features a tert‑butyloxycarbonyl (Boc) protective group attached to the α‑amino group of L‑alanine, leaving the free C‑terminal carboxylic acid available for peptide‑bond formation. This orthogonal protecting group strategy — the Boc group is stable to bases and nucleophiles and is cleaved under mildly acidic conditions (e.g., TFA) — makes Boc‑Ala‑OH the favored N‑protecting‑group building block for Boc‑benzyl (Boc/Bzl) solid‑phase peptide synthesis (SPPS), large‑scale solution‑phase peptide synthesis for generic APIs, and the construction of non‑peptide bioactive frameworks.

With its robust orthogonality to most common reaction conditions, its ability to preserve the stereochemical integrity of the natural L‑alanine in all coupling steps, and its multi‑kilogram scalability, Boc‑Ala‑OH occupies an undisputed position at the very beginning of the modern peptide therapeutics value chain. The compound maintains the chirality of natural L‑alanine throughout synthesis, supporting enantioselective peptide assembly, and its stability and compatibility with a wide array of standard activating reagents (e.g., HATU, HBTU, PyBOP, DCC, EDCI) make it a foundational building block in both manual and automated solid‑phase peptide synthesis (SPPS) and medicinal chemistry.

Core Application Fields

1. Solid‑Phase Peptide Synthesis (SPPS) — The Dominant Demand Driver (≈75‑80% of total consumption).
Boc‑L‑alanine is the most widely used N‑Boc building block in traditional Boc/Bzl SPPS, where the Boc group is progressively deprotected with TFA after each coupling cycle. The compound serves as the protected N‑terminal amino acid unit for incorporating alanine residues into peptide chains during stepwise SPPS, as the key monomer in fully automated synthesizers, and as the standard reference building block for optimizing new coupling reagents and solid‑phase methodologies. Its hydrophilicity, low steric hindrance, and minimal risk of side reactions make it the ideal building block for constructing long or aggregation‑prone peptide sequences. The continued growth of the global peptide therapeutics industry — encompassing GLP‑1 agonists (semaglutide, tirzepatide), peptide vaccines, antimicrobial peptides, and peptide‑drug conjugates (PDCs) — directly drives demand for Boc‑Ala‑OH. The global Boc‑Ala‑NH₂ reagent market was valued at approximately USD 700 million in 2023 and is projected to reach USD 1.4 billion by 2032, exhibiting a CAGR of 8%, and Boc‑L‑alanine occupies the central position at the front end of this multi‑billion‑dollar value chain.

2. Solution‑Phase Peptide Synthesis and Pharmaceutical Intermediate Applications (≈15‑20% of total consumption).
In addition to SPPS, Boc‑L‑alanine is used as a key intermediate in the solution‑phase construction of peptide antibiotics (e.g., daptomycin, colistin), peptide hormone agonists/antagonists, renin inhibitors, and HIV protease inhibitors. It is also employed in the resolution of racemic mixtures of binaphthol‑based chiral auxiliaries and in the one‑pot synthesis of hybrid tripeptidomimetics containing both amide and imide functionalities. Further applications include the preparation of N‑propargylalanine — a key precursor for generating N‑(3‑aryl)propylated alanine residues — and in the production of 5‑O‑(N‑Boc‑L‑alanine)‑renieramycin T (OBA‑RT), a compound that demonstrates cancer stem cell apoptosis via targeting Akt signaling.

3. Cosmetic and Personal Care Applications.
Boc‑L‑alanine finds extensive application in cosmetic and personal care formulations as a surface modifier and conditioning agent. Its compatibility with common cosmetic ingredients, low irritation potential, and ability to enhance skin feel make it a valued ingredient in creams, lotions, and other personal care formulations. The compound is used for protein and peptide synthesis in cosmetic applications, enabling the development of novel bioactive peptides that improve skin elasticity, reduce fine lines, and support overall skin health.

4. Electronics and Printed Circuit Board (PCB) Manufacturing.
Beyond pharmaceutical and cosmetic applications, Boc‑L‑alanine also finds utility in the electronics industry. It serves as an essential component in the manufacturing process of electronic devices, particularly in the production of printed circuit boards (PCBs). Its unique chemical properties enable it to act as a conductor, facilitating the flow of electricity in circuitry, making it an indispensable material for creating reliable and efficient electronic devices.

5. Biochemical Research and Enzymatic Process Exploration.
Boc‑L‑alanine is an essential research tool for studying enzyme kinetics, protein engineering, and biosynthetic pathways that involve alanine incorporation. Researchers harness its versatility in exploring enzymatic processes where precise control over structural modifications is necessary, making it invaluable for academic and industrial research programs.

Major Market Participants

The global supply system for Boc‑L‑alanine follows a pattern of “specialized fine‑chemical and pharmaceutical‑intermediate manufacturers, primarily in China, India, Europe, and the United States, serving both small‑scale R&D and large‑scale industrial production.” Major international suppliers include Sigma‑Aldrich (Merck KGaA), BOC Sciences, MuseChem, and CymitQuimica, with purity grades ranging from 98 % to ≥99.5 % (chiral HPLC), and packaging options ranging from R&D grams to multi‑hundred‑kilogram drums.

Shanghai XinChem Co., Ltd. (XinChem) has established a reliable, fully quality‑controlled supply chain for high‑purity Boc‑L‑alanine (Boc‑Ala‑OH, CAS 15761‑38‑3). Our product meets rigorous pharmaceutical intermediate specifications — purity ≥99.5 % (chiral HPLC), white crystalline powder, specific optical rotation [α]²⁰ᴰ = −25±2 ° (c=1, AcOH), and controlled residual solvents — fully compliant with global SPPS and pharmaceutical intermediate standards. XinChem is well‑positioned to serve the rapidly growing global demand from peptide API manufacturers, CROs/CDMOs, and academic research institutions.

Regulatory and Environmental Considerations

Boc‑L‑alanine (CAS 15761‑38‑3) is classified as an irritant (Xi, Xn) with risk statements R20/21/22 (harmful by inhalation, in contact with skin, and if swallowed) and R36/37/38 (irritating to eyes, respiratory system, and skin). Hazard statements include H302 (harmful if swallowed), H315 (causes skin irritation), H319 (causes serious eye irritation), and H335 (may cause respiratory irritation). The compound should be stored at 2‑8 °C in a dry, sealed container away from light and strong oxidizing agents.

In the European Union, Boc‑L‑alanine is subject to REACH regulations; importers and manufacturers must provide Safety Data Sheets (SDS). In the United States, it is regulated under TSCA as a research chemical. For use in pharmaceutical API synthesis, customers must adhere to cGMP guidelines (21 CFR Parts 210/211). The compound is TSCA listed.

Environmentally, the compound has low predicted aquatic toxicity. Manufacturing generates solvent‑containing waste streams and requires responsible disposal of organic by‑products.

Future Outlook

The market outlook for Boc‑L‑alanine is tied to four core drivers: (1) the continued growth of the global peptide therapeutics market, with the Boc‑Ala‑NH₂ reagent market projected to reach USD 1.4 billion by 2032 (CAGR 8%); (2) the expanding adoption of Boc/Bzl SPPS for manufacturing long and complex peptide sequences; (3) the rapid growth of Asian CRO/CDMO sectors supplying intermediates to global pharmaceutical companies; and (4) the compound‘s expanding applications in cosmetic peptides, PCB manufacturing, and non‑peptide bioactive molecule synthesis.

Enterprises should focus on securing high‑purity (≥99.5 %) production capabilities, maintaining rigorous impurity documentation for pharmaceutical regulatory filings, and building long‑term supply partnerships with peptide API manufacturers, CROs, and research institutions.

Shanghai XinChem Co., Ltd.

As a world‑leading supplier of pharmaceutical intermediates and peptide building blocks, Shanghai XinChem Co., Ltd. (XinChem) has always focused on the innovative needs of the peptide therapeutics, pharmaceutical intermediate, and cosmetic peptide industries. Relying on core advantages in Boc‑chemistry and multi‑step heterocyclic synthesis, purification, and quality assurance, we provide high‑quality Boc‑L‑alanine (CAS 15761‑38‑3) to global customers.

1. Technical Advantages

• High Purity & Consistency: Our Boc‑L‑alanine achieves purity ≥99.5 % (chiral HPLC), white crystalline powder, molecular weight 189.21 g/mol, melting point 79‑83 °C, and moisture <0.5 % (KF titration).
• Low Impurity Profile: Strict control of residual solvents (including trace TFA, DMF), heavy metals (≤10 ppm, ICH Q3D compliant), and optically active impurities ensures high synthetic performance.
• Preserved Chirality: Our product maintains the natural L‑alanine stereochemistry throughout all synthesis steps, supporting enantioselective peptide assembly and preventing D‑Ala incorporation.
• Batch‑to‑Batch Uniformity: Rigorous analytical testing (chiral HPLC, NMR, LC‑MS, heavy metals by ICP‑MS, residual solvents by GC‑headspace) guarantees consistent quality for cGMP pharmaceutical production.

2. Product Advantages

• The Standard Boc‑Building Block for SPPS: Directly used as the key N‑Boc protected amino acid building block in traditional Boc/Bzl SPPS, fully automated peptide synthesizers, and standard manual synthesis workflows.
• Minimal Steric Hindrance: The hydrophobic, low‑bulk L‑alanine residue ensures efficient coupling yields even in long and aggregation‑prone peptide sequences.
• Multi‑Kilogram Scalability: Industrially validated for both research grams (1 g, 5 g, 10 g, 25 g, 50 g, 100 g, 500 g) and bulk production (1 kg, 5 kg, 10 kg, 25 kg, 100 kg+), offering consistent prices and supply security for large‑scale peptide manufacturing.
• Flexible Packaging Options: 5 g, 10 g, 25 g, 50 g, 100 g, 500 g glass bottles (R&D); 1 kg HDPE containers (pilot); 5 kg, 10 kg, 25 kg, 50 kg fiber drums (industrial). Full custom packaging available.
• Reliable Supply Chain: Annual capacity in the multi‑ton range, with dedicated temperature‑controlled warehousing (2‑8 °C, dry, light‑protected) and just‑in‑time delivery capabilities.

3. Application Fields

• Pharmaceutical Intermediates: Peptide therapeutics (GLP‑1 agonists, peptide vaccines, antimicrobial peptides), peptide antibiotics (daptomycin, colistin), HIV protease inhibitors, renin inhibitors, peptide‑drug conjugates (PDCs), and generic peptide APIs.
• Solid‑Phase Peptide Synthesis (SPPS): Standard building block for manual and automated Boc/Bzl SPPS, reference material for coupling reagent optimization, and protected N‑terminal amino acid unit for stepwise peptide chain assembly.
• Cosmetic Peptides: Ingredient for anti‑aging and skin‑care peptides (wrinkle reduction, skin elasticity enhancement, moisturizing formulations), hair‑care peptide conditioning agents, and custom bioactive peptide sequences.
• Electronics & PCB Manufacturing: Essential component in printed circuit board (PCB) production, acting as a conductor and process aid for reliable electronic device manufacturing.
• Biochemical Research: Key tool for studying enzyme kinetics, protein engineering, alanine‑specific biosynthetic pathways, and the preparation of N‑propargylalanine and other unnatural alanine derivatives.

4. Service Support
Our technical team provides full impurity profiling (chiral purity by chiral HPLC, residual solvents by GC‑headspace, heavy metals by ICP‑MS, LC‑MS identity confirmation), custom purification to any desired specification, and complete regulatory documentation (Certificate of Analysis, Technical Data Sheet, Safety Data Sheet, REACH compliance, TSCA certification, DMF support for pharmaceutical customers). We also offer custom synthesis of Boc‑amino acid derivatives, cold‑chain logistics for temperature‑sensitive shipments, and just‑in‑time delivery.

5. Why Choose XinChem

• Professionalism: 20+ years in the pharmaceutical intermediate, Boc‑chemistry, and heterocyclic synthesis industries.
• Flexibility: Tailored to customer purity specifications, packaging sizes, and regulatory documentation requirements.
• Cost‑effectiveness: High purity at competitive industrial pricing.

Contact us now to start cooperation!
Website: www.xinchem.com
Email: sales1@xinchem.com
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