2-Chloromethyl-3,4-Dimethoxy Pyridine Hydrochloride
| Name of Product | 2-Chloromethyl-3,4-Dimethoxy Pyridine Hydrochloride |
|---|---|
| CAS No | 72830-09-2 |
| Therapeutic use:- | Anti-ulcer |
| API Name | Pantoprazole Sodium |
| Formula | C8H10ClNO2 |
| Form:- | API Powder |
| Status | Commercial |
Product Overview
2-Chloromethyl-3,4-dimethoxypyridine hydrochloride, known across the industry simply as the pantoprazole chloro compound, is supplied under CAS 72830-09-2 with the molecular formula C₈H₁₀ClNO₂·HCl and a molecular weight of 224.08.
It is one half of pantoprazole. A pyridine ring carrying methoxy groups at the 3 and 4 positions, and at the 2 position a chloromethyl arm.
That arm is the reactive end: it is displaced by the thiol of the difluoromethoxy benzimidazole fragment to form the thioether that becomes, after oxidation, the sulfoxide at the heart of every proton pump inhibitor.
Which makes the substitution pattern on this pyridine the thing that decides which drug you end up with.
Move the methoxy groups, or replace them with methyl and a trifluoroethoxy, and the same chemistry delivers omeprazole, rabeprazole or lansoprazole instead.
The chloro compounds for all four drugs are commercially traded under near-identical names, which is why the CAS number appears in the title of this page rather than further down.
The material is supplied as the hydrochloride, and that is not a packaging convenience.
The free base is separately registered but is not what anyone ships, for a reason set out in its own section below.
Pantoprazole is a widely prescribed proton pump inhibitor used in erosive oesophagitis, gastro-oesophageal reflux disease and gastric acid hypersecretion, and it is a very large global generic.
Grades and specifications are available on request, and the material is shipped under cold-chain conditions appropriate to its stability.
Actiza Pharma has over 12 years of B2B pharmaceutical export experience, 500+ global clients and a supply footprint across 40+ countries, backed by WHO-GMP and ISO-certified group manufacturing infrastructure in Gujarat, India.
Key Highlights
Supplied as the hydrochloride the salt form that prevents self-alkylation of the free base.
Cold-chain storage and shipping appropriate to the compound’s stability.
12+ years of export experience across 40+ countries.
Application in Synthesis
Applications at a Glance
| Application | Role | Notes |
|---|---|---|
| Pantoprazole sodium manufacture | Supplies the substituted pyridine half of the molecule | The dominant commercial application; a large global PPI generic |
| Substituted pyridine building block chemistry | Activated 2-(chloromethyl)pyridine | Research and development-scale use |
Industry Segments Served
Proton pump inhibitor API manufacturers.
CDMOs and contract synthesis organisations executing client-owned routes.
Analytical and QC laboratories supporting generic filings.
Why It Is a Hydrochloride the Molecule Attacks Itself
This is the most interesting thing about the compound and it explains most of the specification.
Look at what the free base carries. A pyridine nitrogen, which is nucleophilic. And a chloromethyl group two atoms away, which is electrophilic.
Those two functions are perfectly matched, and they are on the same molecule.
In the free base, one molecule’s pyridine nitrogen attacks another molecule’s chloromethyl carbon.
That gives a quaternary pyridinium salt which still carries a chloromethyl arm at the other end, so it happens again. And again.
The free base does not simply decompose it oligomerises, and the process is autocatalytic in the sense that it does not need anything external to start.
Protonating the pyridine nitrogen with hydrochloric acid shuts the reaction down at its source. A protonated nitrogen is not nucleophilic, so it cannot attack anything.
The hydrochloride is therefore a stability strategy, not a crystallisation convenience and it is why the free base, although separately registered under its own CAS number, is not the commercial article.
The Impurities That Matter
The Hydroxy Compound
Water converts the chloromethyl arm into a hydroxymethyl group.
The resulting alcohol cannot displace anything, so it does not participate in the coupling it simply reduces the active content below what the assay suggests and then travels into the customer’s reaction as an unreactive related substance.
It is catalogued as a pantoprazole-related impurity in its own right. Water content and hydroxy compound therefore need individual limits, not a place inside a total.
The Alkylating Alert
A 2-(chloromethyl)pyridine is a reactive alkylating species and a structural alert for mutagenicity under ICH M7.
That is inherent to the molecule rather than an impurity in it, and it is managed by demonstrating purge rather than by removal.
A supplier who quantifies it in the incoming material, and quantifies the related alkylating species alongside it, shortens the customer’s assessment rather than lengthening it.
Technical Specifications
| Parameter | Specification |
|---|---|
| Chemical Name (IUPAC) | 2-(Chloromethyl)-3,4-dimethoxypyridine hydrochloride |
| Common Names | Pantoprazole chloro compound; pantoprazole chloromethyl intermediate |
| CAS Number | 72830-09-2 (free base: 169905-10-6) |
| Molecular Formula | C₈H₁₀ClNO₂ · HCl |
| Molecular Weight | Available on request |
| SMILES | Cl.COc1ccnc(CCl)c1OC |
| MDL / EC Number | Available on request |
| Appearance | Available on request |
| Assay / Purity | Available on request |
| Other Related Substances | Individual and total limits as per in-house standard; reported on COA |
| Water Content (Karl Fischer) | Available on request |
| Identification | IR and ¹H-NMR conform to reference standard |
| Melting Range | Available on request |
| Stage of Synthesis | Key starting material |
| Downstream API | Pantoprazole sodium sesquihydrate; also S-pantoprazole |
| Residual Solvents | As per ICH Q3C |
| Elemental Impurities | Controlled; ICH Q3D statement supplied on request |
| Solubility | Available on request |
| Storage Condition | Available on request |
| Shelf Life | As stated on the batch COA, in unopened original packing under recommended storage |
| GHS Classification | Available on request |
| Transport Classification | Available on request |
Handling & Storage Guidance
The storage requirements here exist to keep the molecule from reacting with itself and with water.
Store refrigerated in tightly closed original packing, protected from moisture.
Allow containers to reach room temperature before opening to prevent condensation on the powder.
Minimise open-container time and re-seal immediately after dispensing.
Keep strictly away from bases any base that deprotonates the pyridinium liberates the free base, which is the unstable form.
Keep away from water and from nucleophiles generally; the chloromethyl arm reacts with both.
Treat the material as an alkylating species for occupational hygiene; avoid skin contact, use gloves and dust control.
Re-test free base, hydroxy compound and assay on any consignment that has experienced a temperature excursion, before charging it into a validated batch.
Consult the Safety Data Sheet supplied with the batch before handling.
Regulatory & Documentation Support
This is a starting material, so a DMF or CEP does not apply to it as a standalone item.
What buyers need is a well-characterised material with documentation supporting their manufacturing filing and their mutagenic impurity assessment.
Documentation Supplied
Certificate of Analysis- batch-specific.
Material Safety Data Sheet in GHS format, with destination-language versions on request.
Technical Data Package- manufacturing flow, analytical methods, specification rationale, impurity profile.
GMP Starting Material declaration under ICH Q7 principles, where the GMP grade is ordered.
ICH Q3C residual solvent and ICH Q3D elemental impurity statements.
Certificate of Origin, Non-GMO declaration, BSE/TSE-free and allergen statements.
Dangerous goods declaration and compliant marking where the classification requires it.
Site audit access, subject to prior scheduling and confidentiality agreement.
Packaging, MOQ & Logistics
| Parameter | Details |
|---|---|
| Standard Packing | Sealed, moisture-barrier containers with desiccant, in protective outer packaging |
| Pack Sizes | Available on request |
| Minimum Order Quantity | Available on request |
| Production Lead Time | Available on request |
| Monthly Capacity | Available on request |
| Sampling | Samples available against request |
| Shipping Terms | FOB / CIF / CFR / EXW, as agreed |
| Cold Chain | Refrigerated shipping with temperature monitoring, appropriate to the storage temperature offered |
| Mode of Transport | Sea and air freight availability available on request, subject to DG classification |
| Port of Loading | Available on request |
| Export Documentation | Standard commercial documentation |
Why Choose Us as Your Supplier
Four near-identically named compounds serve four different proton pump inhibitors. Our documentation carries the CAS number on every page of it, and our commercial team asks which API you are making before quoting.
Batch-to-Batch Consistency
Every batch released against the same analytical protocol with retained samples held for the declared shelf-life.
Export & Client Support
With 12+ years of B2B pharmaceutical export experience, 500+ global clients and shipments across Asia, Africa, Latin America, the CIS region and the Middle East, our commercial and documentation teams work across time zones.
Frequently Asked Questions
Which PPI does this chloro compound make?
Pantoprazole. It is the 3,4-dimethoxy pyridine, CAS 72830-09-2.
Three closely related compounds serve the other proton pump inhibitors the 3,5-dimethyl-4-methoxy pyridine for omeprazole and esomeprazole, the 3-methyl-4-(3-methoxypropoxy) pyridine for rabeprazole, and the 3-methyl-4-(2,2,2-trifluoroethoxy) pyridine for lansoprazole.
All four have near-identical names and are hydrochloride salts, so always order and quote against a CAS number.
Why is it supplied as the hydrochloride rather than the free base?
Because the free base attacks itself. It carries a nucleophilic pyridine nitrogen and an electrophilic chloromethyl group on the same molecule, so one molecule alkylates the next and the material oligomerises.
Protonating the nitrogen removes its nucleophilicity and stops the reaction at source.
The salt is a stability strategy, which is also why the material ships cold.
Why does water matter?
Water converts the chloromethyl arm into a hydroxymethyl group.
The resulting alcohol cannot displace the benzimidazole thiol, so it contributes nothing to your coupling it just lowers your active content and arrives in your reaction as an unreactive related substance.
We control water by Karl Fischer and ship in moisture-barrier packing with desiccant.
Is there an ICH M7 consideration?
Yes. A 2-(chloromethyl)pyridine is a reactive alkylating species and a recognised structural alert for mutagenicity.
That is inherent to the molecule rather than an impurity in it, so it is managed by demonstrating purge into the drug substance.
We provide the quantified data and analytical support your purge argument needs.
How should it be stored?
Refrigerated, tightly closed, protected from moisture, and strictly away from bases anything that deprotonates the pyridinium liberates the unstable free base.
Allow containers to reach room temperature before opening to avoid condensation, and re-seal immediately.
If a consignment has experienced a temperature excursion, re-test free base and hydroxy content before charging it.
Request a Quote
Tell us which proton pump inhibitor you are making, the quantity, the specification and the destination, and our team will respond with pricing, lead time and the documentation set for the pantoprazole chloro compound (CAS 72830-09-2).