Sourcing (R)-(+)-2-Tetrahydrofuroic Acid: Trace Metal & Color Control
Trace Metal Profiling in Bulk (R)-(+)-2-Tetrahydrofuroic Acid: ICP-MS Limits for Fe, Cu, and Mn to Prevent Ring-Opening Oxidation During Esterification
When sourcing (R)-(+)-2-tetrahydrofuroic acid—also referred to as (2R)-Tetrahydrofuran-2-carboxylic acid—for synthetic floral ester precursors, procurement managers must scrutinize trace metal content. Even parts-per-million levels of iron (Fe), copper (Cu), and manganese (Mn) can catalyze unwanted ring-opening oxidation during esterification, leading to off-notes and color bodies in the final fragrance ingredient. At NINGBO INNO PHARMCHEM, our industrial purity grade is controlled via ICP-MS to ensure Fe < 5 ppm, Cu < 2 ppm, and Mn < 1 ppm, effectively mitigating oxidative degradation pathways. This is not a standard specification you'll find on generic datasheets; it's a field-driven parameter we've refined through years of chiral building block manufacturing. For comparison, many bulk suppliers overlook these transition metals, resulting in batch-to-batch variability that can derail your synthesis route. Our drop-in replacement for major catalog products, such as those listed under MFCD00211271, maintains identical reactivity while offering superior trace metal control. For a deeper dive into preventing catalyst-related issues in downstream reactions, see our article on catalyst poisoning prevention in chiral beta-lactam ring closure.
APHA Color Stability Under High-Temperature Esterification: Comparative Distillation Cut Points and Chelation Protocols for Cosmetic-Grade Floral Esters
Color development is a critical quality attribute for cosmetic-grade intermediates. (R)-(+)-2-tetrahydrofuroic acid, as a neat liquid, typically exhibits a colorless to light yellow appearance. However, under the high-temperature conditions of esterification (often 120–150°C), even trace impurities can cause a significant APHA color shift, rendering the final ester unacceptable for premium fragrances. Our manufacturing process employs a narrow distillation cut point (128–129°C at 13 mm Hg) combined with a proprietary chelation protocol that sequesters residual metal ions, ensuring the acid remains below APHA 20 even after prolonged heating. This is a non-standard edge-case behavior we've mastered: while the literature reports a boiling point range, the actual color stability depends heavily on the distillation reflux ratio and the material of construction. We've observed that using 316L stainless steel instead of glass-lined reactors can introduce iron contamination if not properly passivated. For procurement teams evaluating a drop-in replacement for Aldrich-479292, we recommend reviewing our detailed comparison on managing optical drift and trace moisture.
Batch-Specific COA Parameters: Optical Purity, Assay, and Non-Standard Viscosity Behavior at Sub-Ambient Temperatures
Every shipment of (R)-(+)-2-tetrahydrofuroic acid from NINGBO INNO PHARMCHEM includes a comprehensive Certificate of Analysis (COA) detailing assay (typically ≥99% by GC), optical purity ([α]23/D +4°, c = 1 in methanol), and water content. However, one parameter often overlooked is viscosity at sub-ambient temperatures. Field experience shows that this chiral acid exhibits a marked increase in viscosity below 10°C, which can complicate pumping and transfer in non-climate-controlled warehouses. While the density at 25°C is 1.209 g/mL, the viscosity at 5°C can be 2–3 times higher, a behavior not documented in standard references. We advise customers to store and handle the material at room temperature (keep in dark place, sealed in dry) to avoid crystallization or handling difficulties. For exact numerical specifications, please refer to the batch-specific COA, as minor variations may occur due to the synthesis route. Our high assay product is a reliable chiral building block for organic synthesis, particularly in the preparation of faropenem side chain and other pharmaceutical intermediates.
| Parameter | Our Typical Value | Industry Common Range |
|---|---|---|
| Assay (GC) | ≥99.0% | 97–99% |
| Optical Purity | ≥98% ee | 95–98% ee |
| Fe (ICP-MS) | <5 ppm | Often not reported |
| APHA Color (neat) | <20 | Up to 50 |
| Water (KF) | <0.5% | <1.0% |
Bulk Packaging and Logistics: IBC and 210L Drum Options for Supply Chain Reliability Without REACH Claims
For industrial-scale procurement, we offer (R)-(+)-2-tetrahydrofuroic acid in 210L HDPE drums and 1000L IBC totes. Our packaging is designed to maintain product integrity during ocean freight, with nitrogen blanketing available upon request to prevent moisture uptake. As a global manufacturer, we focus on supply chain reliability: our production capacity ensures lead times of 4–6 weeks for bulk orders, and we provide all necessary documentation for customs clearance, including HS Code 29321900. It is important to clarify that we do not claim EU REACH compliance or any environmental certifications; our logistics discussions are strictly limited to physical packaging and safe transport under UN 3265, Class 8, PG III. We recommend storing the material as a combustible corrosive hazardous material (Storage Class 8A) and using appropriate PPE (faceshields, gloves, goggles). For a seamless sourcing experience, explore our product page: high-purity (R)-(+)-2-tetrahydrofuroic acid for chiral synthesis.
Frequently Asked Questions
What are the acceptable APHA color limits for cosmetic-grade intermediates derived from (R)-(+)-2-tetrahydrofuroic acid?
For most cosmetic-grade floral esters, an APHA value below 30 in the final ester is desirable. Our acid, with a neat APHA <20, typically yields esters well within this limit, provided esterification conditions are controlled and trace metals are minimized.
Which chelating agents are effective for furan carboxylic acids to prevent metal-catalyzed discoloration?
In our experience, EDTA and citric acid are effective at sequestering Fe and Cu ions during workup. However, the chelating agent must be thoroughly removed to avoid interference in subsequent reactions. Our in-process chelation protocol is proprietary but ensures residual chelator levels are undetectable in the final product.
What distillation temperature windows should be used to avoid thermal discoloration of (R)-(+)-2-tetrahydrofuroic acid?
We recommend a distillation temperature not exceeding 130°C at 13 mm Hg. Prolonged exposure above this temperature, especially in the presence of oxygen, can lead to yellowing. Our narrow cut point and nitrogen sparging during distillation are critical to maintaining color stability.
How do you prepare furoic acid from furan?
While not directly related to our product, furoic acid is typically prepared by oxidation of furfural. (R)-(+)-2-tetrahydrofuroic acid is a reduced, chiral derivative obtained via asymmetric hydrogenation or resolution of the racemic tetrahydrofuroic acid.
What is tetrahydrofuran OIC acid?
This appears to be a typographical error. The correct term is tetrahydrofuran-2-carboxylic acid, which is synonymous with tetrahydro-2-furoic acid. Our product is the (R)-enantiomer.
What is the density of tetrahydro-2-furoic acid?
The density of (R)-(+)-tetrahydro-2-furoic acid is 1.209 g/mL at 25°C (lit.). This value is consistent across enantiomers.
What is the solubility of 2-furoic acid in water?
2-Furoic acid (the unsaturated analog) is soluble in water. Our tetrahydro derivative is also water-miscible but is typically handled as a neat liquid for esterification reactions.
Sourcing and Technical Support
Securing a reliable supply of (R)-(+)-2-tetrahydrofuroic acid with consistent trace metal and color profiles is essential for fragrance intermediate manufacturers. At NINGBO INNO PHARMCHEM, we combine deep process knowledge with robust logistics to deliver a product that performs as a true drop-in replacement for established catalog items, without the premium pricing. Our technical team is ready to support your scale-up from pilot to production. To request a batch-specific COA, SDS, or secure a bulk pricing quote, please contact our technical sales team.