4F-Methylphenidate (4F-MPH) is methyl 2-(4-fluorophenyl)-2-(piperidin-2-yl)acetate. The content below is written for a research-chemical category page covering 4F-MPH materials. It does not include dosing, administration, or human-use claims. Each product requires its own lot-specific COA confirming identity, salt form, stereochemistry, and assay.

Introduction

4F-MPH is methyl 2-(4-fluorophenyl)-2-(piperidin-2-yl)acetate. It is a fluorinated analogue of methylphenidate. A fluorine atom sits at the para (4-) position of the phenyl ring, a methyl ester sits on the acetate side chain, and a piperidin-2-yl group is attached at the alpha carbon. It is the para-fluoro isomer of other ring-fluorinated methylphenidate analogues and is not methylphenidate, which has no fluorine. The structure has two stereocenters; the threo relative configuration is the form commonly associated with the parent compound.

It is not an approved medicine. The free base is C₁₄H₁₈FNO₂, 251.30 g·mol⁻¹, commonly associated with CAS 1354631-33-6. The hydrochloride, if supplied, must be stated on the COA (approximate mass 287.8 g·mol⁻¹). Products in this category (powder, pellets, or other forms) must state free base versus hydrochloride and the relative stereochemistry (threo or erythro, racemate or named enantiomer) on the label and COA. A category name does not confirm the salt or stereochemistry of any individual lot.

Key Features & Benefits

• Defined para-fluoro methylphenidate analogue. The 4-fluoro substitution is the structural marker that distinguishes it from the parent and from meta or ortho isomers.
• Documented identity: free-base formula C₁₄H₁₈FNO₂, CAS 1354631-33-6 commonly cited.
• Fluorine marker. ¹⁹F NMR can confirm the para-fluoro pattern.
• Distinct from methylphenidate. That compound has no fluorine (free-base CAS 113-45-1, C₁₄H₁₉NO₂, 233.31 g·mol⁻¹).
• Suitable for controlled laboratory and forensic analytical work when legally authorized. Not for formulation or human administration.

Specifications Table

Applications in Research

Appropriate uses are non-clinical, institutionally approved, and legally authorized:

• Analytical reference material for HPLC, LC-MS, and NMR identification of 4F-MPH against a certified standard.
• Forensic differentiation from methylphenidate and from other ring-fluorinated methylphenidate isomers.
• Comparison of free-base versus hydrochloride lots and of different stereoisomeric forms.
• In vitro dopamine-transporter assays where the protocol specifically covers this compound.

Do not describe or imply oral, insufflation, injection, or any other human route of administration. Do not treat any labeled milligram quantity as a dose.

Purity & Testing

A defensible product claim rests on the batch certificate of analysis for the specific form.

• HPLC for chromatographic purity, with retention that separates the 4-fluoro isomer from other ring-fluoro isomers and from methylphenidate.
• ¹H NMR and/or ¹⁹F NMR confirming the para-fluoro aromatic pattern, the methyl ester, and the piperidine ring. An ortho or meta pattern indicates a different isomer; absence of fluorine indicates methylphenidate.
• Mass spectrometry consistent with the free-base molecular ion of C₁₄H₁₈FNO₂.
• Explicit statement of free base or named salt and of relative stereochemistry.
• Residual solvent and related-substance limits if stated by the supplier.

Store the COA with the lot number. Do not use a methylphenidate CAS number for a 4F-MPH lot.

Disclaimer

For laboratory research use only, where legally authorized. Not for human or veterinary consumption, not for diagnostic or therapeutic use, and not a food, drug, or cosmetic. 4F-MPH is restricted under the German NpSG and under the Psychoactive Substances Act in the United Kingdom. Methylphenidate is a controlled substance in many jurisdictions, and analogue rules may apply. Unauthorized possession, manufacture, distribution, or importation can be a criminal offense. Buyers are solely responsible for confirming legality, licensing, import rules, and institutional approval before ordering or handling any specific product. Handle under applicable controlled-substance and hazardous-chemical rules and dispose of waste according to local regulations. No statement on this page is a claim of safety, efficacy, or fitness for any human application. The category name does not replace lot-specific identity and purity data on the COA.

Frequently Asked Questions

What is 4F-MPH?
It is methyl 2-(4-fluorophenyl)-2-(piperidin-2-yl)acetate, also called 4-fluoromethylphenidate. The free base is C₁₄H₁₈FNO₂, 251.30 g·mol⁻¹.

Is the product the free base?
Not unless the COA says so. The hydrochloride weighs approximately 287.8 g·mol⁻¹. The COA must state the form.

Is this the same as methylphenidate or other fluoro isomers?
No. Methylphenidate has no fluorine (free-base CAS 113-45-1). Other fluoro isomers have the fluorine at different ring positions. 4F-MPH is the para-fluoro compound, free-base CAS 1354631-33-6 commonly cited. Mass alone does not separate the fluoro isomers.

Which CAS number applies?
CAS 1354631-33-6 is commonly cited for the free base. Confirm free base versus salt and stereochemistry on the COA.

What purity is supplied?
Only the value stated on the specific lot COA, together with the analytical method. The method should resolve 4F-MPH from related isomers.

How should it be stored?
Sealed, cool, dry, and protected from light under the rules that apply. Keep the lot number with the COA.

Can it be used in humans?
No. It is not an approved medicine and is not sold for consumption. Check local law before purchase or handling.

What analytical methods confirm identity?
HPLC with isomer resolution, NMR (including ¹⁹F) for the para-fluoro, methyl ester, and piperidine pattern, and mass spectrometry consistent with C₁₄H₁₈FNO₂. An ortho or meta aromatic pattern or missing fluorine means the sample is not 4F-MPH. The COA should state free base or salt and stereochemistry.