Chiral Herbicide Intermediates: O-Tert-Butyl-D-Serine Methyl Ester HCl
Technical Specifications and Purity Grades for O-tert-Butyl-D-serine Methyl Ester Hydrochloride in Chiral Herbicide Synthesis
O-tert-Butyl-D-serine methyl ester hydrochloride, often referred to as H-D-Ser(tBu)-OMe hydrochloride or D-Ser(OtBu)-OMe.HCl, serves as a critical chiral building block in the synthesis of enantiomerically pure herbicides. This compound, with CAS 78537-14-1, is a white to off-white crystalline powder that provides the D-serine backbone necessary for constructing active pharmaceutical and agrochemical ingredients. In herbicide manufacturing, the tert-butyl protecting group on the hydroxyl functionality allows for selective deprotection under mild acidic conditions, enabling precise control over the synthetic route. The methyl ester moiety facilitates peptide coupling reactions, making it an ideal intermediate for building complex chiral molecules.
Industrial-grade material typically meets a purity specification of ≥98.0% by HPLC, with the enantiomeric excess (ee) exceeding 99.0% as determined by chiral HPLC. This high enantiopurity is essential because, as seen with herbicides like 2-(2-chlorophenoxy)propanoic acid, only one enantiomer exhibits the desired biological activity. The R-enantiomer of that herbicide shows significantly higher auxinic activity, and similar stereospecificity applies to many modern agrochemicals. Our O-tert-butyl-D-serine methyl ester hydrochloride is manufactured under strict quality control to ensure batch-to-batch consistency, making it a reliable choice for chiral herbicide intermediates.
| Parameter | Specification |
|---|---|
| Appearance | White to off-white crystalline powder |
| Purity (HPLC) | ≥98.0% |
| Enantiomeric Excess (ee) | ≥99.0% |
| Melting Point | Please refer to the batch-specific COA |
| Specific Rotation | Please refer to the batch-specific COA |
| Water Content (KF) | ≤0.5% |
For procurement managers, understanding these specifications is crucial when sourcing chiral intermediates. The high ee value directly impacts the yield and purity of the final herbicide, reducing the need for additional purification steps. As a global manufacturer, NINGBO INNO PHARMCHEM CO.,LTD. ensures that each batch is accompanied by a comprehensive Certificate of Analysis (COA), providing full transparency on these critical parameters.
Batch-Specific Certificate of Analysis (COA) Parameters and Non-Standard Quality Metrics
Beyond the standard purity and enantiomeric excess, our COA includes several non-standard parameters that reflect hands-on field knowledge. One such parameter is the trace impurity profile, which can significantly affect downstream reactions. For instance, residual solvents like ethyl acetate or methanol, if present above certain thresholds, can interfere with sensitive catalytic steps. Our manufacturing process controls these to levels typically below 0.1%, but exact values are batch-dependent and documented in the COA.
Another critical metric is the chloride content, which must be stoichiometrically accurate for the hydrochloride salt. Deviations can indicate incomplete salt formation or the presence of free base, affecting solubility and reactivity. We also monitor for the presence of the undesired L-enantiomer, which, even at trace levels, can compromise the chiral purity of the final herbicide. This is particularly important when the intermediate is used in the synthesis of compounds like Dimethenamid-P, where the S-isomer is the active component. Our chiral HPLC methods are validated to detect the L-isomer at levels as low as 0.1%.
In our experience, a non-standard parameter that often goes overlooked is the material's behavior upon prolonged storage. We have observed that under high humidity conditions, the ester moiety can undergo slow hydrolysis, leading to the formation of O-tert-butyl-D-serine. This degradation product can act as an impurity in subsequent peptide couplings. Therefore, we recommend storage under inert atmosphere at -20°C and include a retest date on the COA based on accelerated stability studies. For bulk purchasers, we provide guidance on proper storage to maintain integrity, as detailed in our article on bulk IBC handling to prevent moisture-induced ester hydrolysis.
Industrial-Scale Handling, Crystallization Behavior, and Bulk Packaging Logistics
Handling O-tert-Butyl-D-serine methyl ester hydrochloride at an industrial scale requires attention to its physical properties. The compound is a crystalline solid at room temperature but can exhibit hygroscopic tendencies if not properly sealed. In our production facility, we have noted that the crystallization behavior is influenced by the cooling rate during the final purification step. Rapid cooling can lead to a finer powder with lower bulk density, which may affect flowability in automated dispensing systems. To mitigate this, we employ a controlled cooling process that yields a consistent particle size distribution, typically with a bulk density of approximately 0.5 g/mL. This ensures reliable handling in large-scale synthesis.
For bulk packaging, we offer standard options including 25 kg fiber drums with inner PE liners, as well as larger IBC totes for high-volume customers. The choice of packaging is critical to prevent moisture ingress, which can initiate ester hydrolysis. Our drums are purged with nitrogen before sealing, and we include desiccant packs for added protection. When shipping to regions with high ambient humidity, we recommend that customers transfer the material under dry conditions and avoid prolonged exposure to air. The logistics of transporting this chiral intermediate are straightforward, as it is classified as non-hazardous for transport. However, we always advise consulting the Safety Data Sheet (SDS) for specific handling precautions.
In terms of supply chain reliability, we maintain safety stock of key intermediates to buffer against production fluctuations. This is particularly important for customers who rely on just-in-time delivery for their herbicide manufacturing campaigns. Our production capacity allows us to fulfill orders ranging from kilogram to multi-ton quantities, with lead times typically 4-6 weeks for custom batches. For those seeking a direct replacement for existing suppliers, we have demonstrated equivalency with products like Fluorochem F045368, as discussed in our article on limits for trace metals as a direct replacement for Fluorochem F045368.
Drop-in Replacement Strategy: Cost Efficiency and Supply Chain Reliability for Chiral Intermediates
For procurement managers evaluating O-tert-Butyl-D-serine methyl ester hydrochloride, the concept of a "drop-in replacement" is central to minimizing requalification costs. Our product is manufactured to match the specifications of leading global suppliers, ensuring that it can be seamlessly substituted without altering existing synthetic protocols. This is achieved by rigorous control of critical parameters such as purity, enantiomeric excess, and impurity profile. In many cases, our material has been successfully used as a direct replacement in the synthesis of chiral herbicides, with no impact on yield or product quality.
Cost efficiency is a key driver in the agrochemical industry, where margins are tight. By sourcing from NINGBO INNO PHARMCHEM CO.,LTD., customers can achieve significant savings compared to traditional Western suppliers, without compromising on quality. Our competitive pricing is a result of optimized manufacturing processes and economies of scale. Additionally, our supply chain reliability is bolstered by multiple production lines and a robust logistics network, ensuring that even during global disruptions, we can maintain delivery schedules. This is critical for herbicide manufacturers who cannot afford production downtime.
When considering a switch, we recommend a simple qualification protocol: compare the COA of our batch against your current supplier's, perform a small-scale test reaction, and analyze the final product for purity and chiral integrity. In our experience, the transition is smooth, and many customers report equivalent or better performance. Our technical team is available to support this process, providing sample quantities and detailed analytical data. The goal is to offer a risk-free alternative that enhances your supply chain resilience.
Field-Validated Performance: Viscosity Shifts and Trace Impurity Profiles in Herbicide Manufacturing
In real-world herbicide manufacturing, the behavior of intermediates can deviate from ideal conditions. One non-standard parameter we have investigated is the viscosity shift of reaction mixtures containing O-tert-Butyl-D-serine methyl ester hydrochloride at sub-zero temperatures. During large-scale peptide couplings, the reaction mixture is often cooled to control exotherms. We have observed that at temperatures below -10°C, the solubility of the hydrochloride salt in common solvents like DMF or dichloromethane decreases, leading to a noticeable increase in viscosity. This can affect mixing efficiency and heat transfer. To address this, we recommend pre-dissolving the intermediate at room temperature and adding it slowly to the cooled reaction mixture, or using a solvent blend that maintains lower viscosity. This insight comes from hands-on experience in scaling up reactions and is not typically found in standard specification sheets.
Another field observation relates to trace impurities that can affect the color of the final herbicide. Even when the intermediate meets purity specifications, the presence of trace metals like iron or copper at ppm levels can catalyze side reactions, leading to discoloration. Our manufacturing process includes a chelating agent wash step to reduce metal content, and we monitor these levels by ICP-MS. For customers synthesizing herbicides that require a pure white appearance, this attention to detail is crucial. We have also noted that the tert-butyl protecting group can undergo slight thermal decomposition if exposed to temperatures above 40°C for extended periods, releasing isobutylene gas. Therefore, we advise against storing the material in hot warehouses and recommend climate-controlled storage for long-term stability.
These field-validated insights ensure that our product not only meets analytical specifications but also performs reliably under actual manufacturing conditions. By sharing this knowledge, we help our customers avoid common pitfalls and optimize their processes.
Frequently Asked Questions
What is the minimum order quantity (MOQ) for O-tert-Butyl-D-serine methyl ester hydrochloride?
Our standard MOQ is 1 kg for sample evaluation. For commercial production, we can supply from 25 kg to multi-ton quantities. Please contact our sales team for a tailored quote based on your annual volume requirements.
Can you provide a Certificate of Analysis (COA) before purchase?
Yes, we provide a representative COA for the current batch upon request. Each shipment includes a batch-specific COA with actual test results for purity, enantiomeric excess, and other parameters.
What are the payment terms and delivery conditions?
We typically operate on a T/T (telegraphic transfer) basis with 30% advance and 70% against shipping documents. For established customers, we offer net 30-day terms. Delivery terms are usually FOB Shanghai or CIF destination port, depending on customer preference.
How do you ensure the chiral purity of the product during transportation?
The product is stable under recommended storage conditions. We package in airtight containers under nitrogen and include desiccants. We also provide handling guidelines to prevent moisture uptake, which could lead to hydrolysis and potential racemization.
Is your product a direct replacement for other suppliers' O-tert-Butyl-D-serine methyl ester hydrochloride?
Yes, our product is designed as a drop-in replacement. We match or exceed the specifications of major suppliers. We recommend a small-scale qualification to confirm compatibility with your specific process, and our technical team can assist with this evaluation.
Sourcing and Technical Support
In summary, O-tert-Butyl-D-serine methyl ester hydrochloride is a versatile chiral intermediate for herbicide synthesis, and NINGBO INNO PHARMCHEM CO.,LTD. offers a reliable, cost-effective supply with comprehensive technical support. Our commitment to quality, from batch-specific COAs to field-validated handling advice, ensures that your manufacturing process runs smoothly. Whether you are scaling up a new herbicide or seeking a second source for an existing product, our team is ready to assist. For custom synthesis requirements or to validate our drop-in replacement data, consult with our process engineers directly.