Guaiacol (2-Methoxyphenol)
CAS 90-05-1 | C7H8O2 | MW 124.14
Guaiacol is a naturally occurring methoxyphenol found in guaiac resin and wood smoke, valued across the pharmaceutical, flavor-and-fragrance, and fine-chemical industries. As the essential starting material for guaifenesin and the primary feedstock for synthetic vanillin, Guaiacol bridges healthcare and the global food supply chain. Chelora PharmaChem delivers it in Pharma IP, Technical, and High-Purity grades with full analytical documentation and worldwide shipping capability.
Physical Form
Liquid & Crystal
MP 26–29 °C
≥ 99.0 %
Pharma-Grade Purity
124.14
Molecular Weight
Non-DG
Transport Classification
Global
Export Capability
The Essential Methoxyphenol for Pharma & Flavor
Guaiacol (2-Methoxyphenol, CAS 90-05-1) is a phenolic compound with the molecular formula C6H4(OH)(OCH3). It presents as a colorless to pale-yellow crystalline solid at temperatures below its melting range of 26–29 °C, transitioning to an oily liquid with a distinctive smoky, aromatic odour above that threshold. The compound occurs naturally in guaiac resin, wood smoke, and roasted coffee, but commercial demand is met almost entirely by synthetic production from catechol.
In the pharmaceutical sector, Guaiacol occupies a position of strategic importance as the exclusive starting material for guaifenesin (glyceryl guaiacolate), the globally dominant expectorant active pharmaceutical ingredient. The reaction pathway—etherification of guaiacol with glycidol or 3-chloro-1,2-propanediol—is practiced at scale by every major guaifenesin manufacturer. Beyond expectorants, the molecule serves as a precursor to methocarbamol (a centrally acting skeletal muscle relaxant) and an expanding portfolio of development-stage APIs.
In the flavor and fragrance arena, guaiacol is the primary raw material for the synthesis of vanillin by catalytic oxidation, a process that supplies the vast majority of the world’s vanillin. It also feeds into eugenol chemistry, linking it to dental materials, perfumery bases, and spice-oil reconstitutions.
Chelora PharmaChem supplies Guaiacol in three specification tiers—Pharma IP (≥ 99.0 %), Technical (≥ 98.0 %), and High-Purity Reagent (≥ 99.5 %)—to serve regulated API synthesis lines, large-scale vanillin plants, and analytical laboratories alike. Every shipment is backed by a lot-specific Certificate of Analysis, Safety Data Sheet, and export documentation for frictionless clearance at destination ports worldwide.
Technical Data Sheet
| Parameter | Value |
|---|---|
| CAS Number | 90-05-1 |
| IUPAC Name | 2-Methoxyphenol |
| Molecular Formula | C₇H₈O₂ |
| Molecular Weight | 124.14 g/mol |
| Appearance | Colorless to yellowish crystalline mass or oily liquid with characteristic smoky odour |
| Melting Point | 26–29 °C |
| Boiling Point | 204–206 °C |
| Density | ~1.129 g/cm³ (liquid at 25 °C) |
| Solubility (Water) | Slightly soluble (~17 g/L at 20 °C) |
| Solubility (Ethanol) | Freely soluble |
| Purity (Typical) | ≥ 99.0 % |
| Flash Point | 82 °C (closed cup) |
| pH (1 % aq.) | 4.0–6.0 |
| Loss on Drying | ≤ 0.5 % |
| Residue on Ignition | ≤ 0.05 % |
| Storage | Cool, dry, dark place; protect from air and light |
| Transport Classification | Non-DG (not classified as dangerous goods) |
Synonyms: o-Methoxyphenol, Methylcatechol, o-Hydroxyanisole. Also written as C6H4(OH)(OCH3).
From Cough Syrup to Vanilla Ice Cream
Guaiacol is one of the rare chemical intermediates that touch everyday life across multiple sectors. Here are its principal downstream applications.
Guaifenesin (Expectorant) Synthesis
Guaiacol is the single most critical raw material for the manufacture of guaifenesin, the world’s most widely prescribed expectorant. The glyceryl ether linkage is formed directly from guaiacol in a well-established catalytic process used by every major guaifenesin producer.
Vanillin Synthesis
Synthetic vanillin—the most consumed flavoring compound on Earth—is produced primarily by the catalytic oxidation of guaiacol. The Rhône-Poulenc and Borregaard processes both begin with guaiacol, making it indispensable to the global flavor and fragrance industry.
Eugenol & Fragrance Intermediates
Guaiacol serves as a versatile precursor to eugenol and related allylphenols that are central to perfumery, dental materials, and essential oil formulations. Its phenolic hydroxyl and methoxy groups provide the molecular handles needed for downstream transformations.
Pharmaceutical API Intermediates
Beyond guaifenesin, guaiacol is a building block for methocarbamol (a centrally-acting muscle relaxant), various cough and cold formulations, and a growing family of novel API intermediates undergoing clinical evaluation in respiratory and CNS therapeutic areas.
Antioxidant in Food & Polymer Applications
The electron-rich aromatic ring of guaiacol confers effective radical-scavenging activity. It is used as an antioxidant additive in select food-contact polymers, specialty resin systems, and as a reference antioxidant standard in food-science research.
Veterinary Medicine
In veterinary practice, guaiacol-based formulations are administered to livestock—particularly cattle and equines—for the management of respiratory congestion and mucus clearance, mirroring its human expectorant pharmacology at species-appropriate doses.
Three Specifications, One Commitment to Quality
Whether your process demands pharmacopoeial compliance, industrial throughput, or analytical precision, Chelora PharmaChem has the right grade of Guaiacol for you.
Pharma / IP Grade
≥ 99.0 %
Guaifenesin API synthesis, pharmaceutical intermediates, regulated manufacturing
Technical Grade
≥ 98.0 %
Vanillin production, eugenol intermediates, industrial antioxidant applications
High-Purity / Reagent Grade
≥ 99.5 %
Analytical research, reference standards, academic R&D
Safely Packed, Fully Documented
Guaiacol is sensitive to oxidation and light exposure. Our packaging is engineered to preserve product quality from the production floor to your receiving dock, using opaque, air-tight containers that conform to international freight regulations.
Packaging Options
- 25 kg HDPE drums (liquid or solidified form)
- 50 kg MS drums with HDPE liner for bulk orders
- Sample quantities in amber glass bottles
Documentation Included
- Certificate of Analysis (COA)
- Safety Data Sheet (SDS / MSDS)
- Product Specification Sheet
- Stability Data (where available)
Frequently Asked Questions
Is Guaiacol a liquid or a solid?
Guaiacol has a melting point of 26–29 °C, so it exists as a crystalline solid at room temperature in cooler climates and as an oily liquid in warmer conditions. We supply it in both forms—as a solidified crystalline mass in HDPE drums or as a liquid—depending on your process requirements. The chemical identity and purity are identical regardless of physical state.
What purity grades of Guaiacol does Chelora PharmaChem offer?
We offer three grades: Pharma / IP grade (≥ 99.0 %) for guaifenesin API synthesis and regulated pharmaceutical manufacturing, Technical grade (≥ 98.0 %) for vanillin production and industrial applications, and High-Purity / Reagent grade (≥ 99.5 %) for analytical research and reference standards. Each lot ships with a Certificate of Analysis.
Is Guaiacol hazardous for shipping?
No. Guaiacol is classified as non-dangerous goods (Non-DG) for transport purposes. It does not fall under any UN hazard class for road, sea, or air freight, which simplifies logistics and reduces shipping costs for international buyers.
What is the primary pharmaceutical use of Guaiacol?
The dominant pharmaceutical application is as the key starting material for the synthesis of guaifenesin (glyceryl guaiacolate), the world’s most widely used expectorant found in hundreds of over-the-counter cough and cold formulations. It is also used in the manufacture of methocarbamol, a muscle relaxant.
What is the shelf life of Guaiacol?
When stored properly—in a cool, dry, dark place, protected from air and light—Guaiacol has a shelf life of 24 months from the date of manufacture. The product should be kept in tightly sealed original containers to minimize oxidation and discoloration.
Does Chelora PharmaChem export Guaiacol internationally?
Yes. We export Guaiacol to pharmaceutical manufacturers, vanillin producers, and chemical distributors worldwide. Our export documentation includes COA, SDS, and all certificates required for customs clearance in your destination country. We have experience shipping to markets across Asia, the Middle East, Africa, Europe, and the Americas.
Explore Our Product Range
Chelora PharmaChem manufactures and exports a broad portfolio of pharmaceutical intermediates, fine chemicals, and speciality reagents. Explore the products below or contact us for a custom requirement.
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