2-(2-(2-Aminoethoxy)ethoxy)acetic acid hydrochloride

Many PEG linkers require Fmoc or Boc removal before use — a step that consumes time, solvents, and often requires chromatographic purification. 2-(2-(2-Aminoethoxy)ethoxy)acetic acid hydrochloride eliminates this issue: here, the amine is presented as the HCl salt, which is stable at room temperature under inert atmosphere and can be stored without special cold chain (though recommended storage is inert atmosphere, room temperature). With 2-(2-(2-Aminoethoxy)ethoxy)acetic acid hydrochloride, the free base is generated in situ by adding a mild base (e.g., DIPEA, TEA) before coupling. The terminal carboxylic acid of 2-(2-(2-Aminoethoxy)ethoxy)acetic acid hydrochloride can be activated via standard amide coupling reagents (HATU, EDC/NHS) to react with amine‑containing payloads, proteins, or peptides. This linker — 2-(2-(2-Aminoethoxy)ethoxy)acetic acid hydrochloride — is widely used as a research chemical for constructing ADCs, PROTACs, PEGylated drugs, and as an intermediate in pharmaceutical synthesis.

Product Parameters

Production Method (Synthesis Overview)

The compound is prepared from a Boc‑protected precursor. A typical laboratory synthesis (as per literature):

1.Starting material: 2‑[2‑(tert‑butoxycarbonylamino)ethoxy]ethoxyacetic acid (Boc‑NH‑PEG2‑CH₂COOH, ~2.4 g).

2.Deprotection: The Boc‑protected material is dissolved in ethyl acetate (20 mL) and cooled to 0 °C.

3.HCl addition: 20 mL of 7 M HCl in ethyl acetate is added dropwise.

4.Monitoring: The reaction is followed by TLC until completion.

5.Concentration: The solvent is removed under reduced pressure to yield the product as an oily residue, which solidifies upon standing to a white to off‑white solid.

Cosperpharm scales this process under controlled conditions, ensuring high purity and low residual solvents. The final product is dried and packaged under inert atmosphere to maintain stability.

Frequently Asked Questions (FAQ)

Q1: How do I use this linker in a conjugation reaction?

A: To use the amine, first neutralize the HCl salt by adding 1.0–1.1 equivalents of a non‑nucleophilic base (DIPEA, TEA) in an aprotic solvent (DMF, DCM). For the carboxylic acid activation, use HATU/DIPEA or EDC/NHS in DMF or water (pH 5.5–6.5). The two functional groups are orthogonal; you can selectively protect one if needed.

Q2: Do I need to store this product in a freezer?

A: No. The recommended storage is inert atmosphere (argon or nitrogen) at room temperature. The hydrochloride salt is stable and does not require cold storage. Avoid prolonged exposure to air (amine can absorb CO₂) and moisture.

Ordering Information

Ready to use CAS 134979‑01‑4 (NH₂‑PEG2‑CH₂COOH·HCl) in your next ADC, PROTAC, or bioconjugation project? Request a sample or a quote from Cosperpharm today. We are a reliable supplier of high‑purity PEG linkers and pharmaceutical intermediates.