What Is Methyl 2-Aminopent-4-enoate Hydrochloride?

Methyl 2-aminopent-4-enoate hydrochloride is the hydrochloride salt of the methyl ester of allylglycine, a non-proteinogenic α-amino acid. Its molecular formula is C₆H₁₂ClNO₂. The compound possesses three synthetically useful functional groups on the same scaffold: a protonated primary amine (delivered as a stable, easily handled hydrochloride salt), a methyl ester, and a terminal alkene (allyl group). This combination makes it a highly attractive bifunctional building block for medicinal chemists and peptide chemists alike.

The terminal alkene is orthogonal to standard peptide-coupling conditions, meaning it can be introduced into a peptide chain and later elaborated—for example, by ring-closing metathesis (RCM), cross-metathesis, or thiol-ene reactions—without interfering with amide bond formation steps.

Key Synthetic Applications

Methyl 2-aminopent-4-enoate hydrochloride serves as a starting material or intermediate in several important synthetic contexts:

• Peptide synthesis: After free-basing or directly under coupling conditions with base, the α-amino group participates in standard amide bond-forming reactions (EDC/HOBt, HATU, or Boc/Fmoc SPPS strategies). The allyl side chain is preserved and can be exploited in subsequent transformations.
• Ring-closing metathesis (RCM): When two allyl-containing residues are incorporated into a linear peptide, Grubbs-type ruthenium catalysts can cyclize the chain to form constrained, macrocyclic or bicyclic peptidomimetics with improved proteolytic stability.
• Cross-coupling and functionalization: The terminal alkene undergoes hydroboration–oxidation, dihydroxylation, epoxidation, or Heck-type coupling to introduce hydroxyl, epoxide, or aryl groups, expanding structural diversity.
• Total synthesis: The compound is used as a chiral pool or racemic starting material for natural product synthesis where an allylglycine fragment is required.

Because the amine is masked as a hydrochloride salt, the reagent is bench-stable and can be stored and weighed conveniently without special precautions beyond standard moisture control.

Handling, Storage, and Safety

Physical form: Typically supplied as a white to off-white crystalline powder.

Storage: Store in a tightly sealed container in a cool (2–8 °C recommended for long-term stability), dry location away from incompatible materials such as strong oxidizers and strong bases. The hydrochloride salt form confers significantly greater hygroscopic stability compared to the free base; nonetheless, minimize exposure to atmospheric moisture.

Handling: Use standard laboratory personal protective equipment (PPE): nitrile gloves, safety goggles, and a laboratory coat. Work in a well-ventilated area or fume hood. As with all fine chemical powders, avoid generating and inhaling dust.

Disposal: Follow your institution's chemical waste disposal regulations. Do not pour down the drain without confirming local regulations permit it.

Note: Specific GHS hazard classifications and a full Safety Data Sheet (SDS) should be obtained from Aladdin Scientific's product page for SKU M725839 before use.

Solubility and Reaction Setup Tips

Solubility: Methyl 2-aminopent-4-enoate hydrochloride is generally soluble in polar protic solvents such as water, methanol, and ethanol. Solubility in DMSO is also expected. It has limited solubility in non-polar organic solvents such as hexane, toluene, or diethyl ether.

Free-basing for reactions: When the free amine form is needed for coupling reactions or other transformations requiring a neutral amine nucleophile, the hydrochloride salt can be converted by treatment with an appropriate base (e.g., triethylamine, DIPEA, or Na₂CO₃ solution). In SPPS, the hydrochloride is typically added to the coupling mixture with 2–3 equivalents of tertiary amine base.

Concentration and scale: Weigh the compound promptly and return to storage to minimize moisture uptake. For stock solutions, prepare fresh and store refrigerated if not used immediately.

Racemic vs. enantiopure: Confirm whether a racemic (DL) or enantiopure (L or D) form is required for your application. Contact Aladdin Scientific technical support to confirm the stereochemical specification of the lot you are purchasing.

Quality, Purity, and Regulatory Considerations

Purity: Aladdin Scientific's Methyl 2-aminopent-4-enoate hydrochloride (SKU M725839) is supplied as a research-grade reagent. Typical purity is confirmed by standard analytical techniques such as HPLC, NMR, and elemental analysis or mass spectrometry. Always refer to the Certificate of Analysis (CoA) supplied with the specific lot number for exact purity data.

Research use only: This compound is intended for laboratory research purposes only and is not approved or certified for use in clinical, diagnostic, or food applications.

Lot-to-lot consistency: Aladdin Scientific performs quality control on each lot. If your application is sensitive to trace impurities (e.g., asymmetric catalysis or highly sensitive biological assays), request the CoA before ordering or contact technical support for additional analytical data.

Export/regulatory: This reagent is not classified as a controlled substance under standard chemical control schedules, but always verify applicable local import/export regulations before ordering internationally.