N-(Boc-PEG1)-N-bis(PEG2-propargyl)
[CAS# 2100306-63-4]

Identification

• Classification: Organic raw materials >> Carboxylic compounds and derivatives >> Carboxylic esters and their derivatives
• Name: N-(Boc-PEG1)-N-bis(PEG2-propargyl)
• Synonyms: tert-butyl N-[2-[2-[bis[2-(2-prop-2-ynoxyethoxy)ethyl]amino]ethoxy]ethyl]carbamate
• Molecular Formula: C₂₃H₄₀N₂O₇
• Molecular Weight: 456.57
• CAS Registry Number: 2100306-63-4
• SMILES: CC(C)(C)OC(=O)NCCOCCN(CCOCCOCC#C)CCOCCOCC#C

Properties

• Density: 1.1±0.1 g/cm³, Calc.^*
• Index of Refraction: 1.483, Calc.^*
• Boiling Point: 535.4±50.0 ºC (760 mmHg), Calc.^*
• Flash Point: 277.6±30.1 ºC, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H302-H315-H319
• Precautionary Statements: P501-P270-P264-P280-P302+P352-P337+P313-P305+P351+P338-P362+P364-P332+P313-P301+P312+P330

Discovory and Applicatios

N-(Boc-PEG1)-N-bis(PEG2-propargyl) is a multifunctional polyethylene glycol (PEG)-based compound that features a tert-butoxycarbonyl (Boc) protected amine and two propargyl-terminated PEG chains. The molecule contains distinct PEG units of varying lengths, typically involving ethylene glycol repeat units to enhance hydrophilicity and solubility, while the propargyl groups provide alkyne functionalities useful for subsequent conjugation via click chemistry.

The development of PEG-based multifunctional linkers such as N-(Boc-PEG1)-N-bis(PEG2-propargyl) can be traced to the broader field of biomedical and chemical synthesis that emerged during the late 20th century, especially in response to increasing demand for hydrophilic and biocompatible chemical handles. PEGylation, the covalent attachment of PEG chains to bioactive molecules, was initially pursued to improve the pharmacokinetic properties of drugs and proteins by increasing solubility, reducing immunogenicity, and enhancing circulation half-life. The ability to design PEG molecules with orthogonal reactive groups led to the emergence of branched and multifunctional PEG derivatives tailored for specific synthetic and biological applications.

The Boc group in N-(Boc-PEG1)-N-bis(PEG2-propargyl) serves as a temporary protecting group for the primary amine. This protection enables selective deprotection under acidic conditions, allowing the amine to be activated at a desired stage in a synthetic sequence. Such protecting strategies are common in peptide synthesis, drug conjugation, and polymer modification workflows.

The two propargyl (alkyne) termini offer chemical handles for Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC), a widely used variant of click chemistry. This reaction is known for its high selectivity, bioorthogonality, and efficiency under mild conditions, making this compound a valuable building block for bioconjugation and surface modification. Typical applications involve attachment to azide-functionalized peptides, proteins, fluorophores, nanoparticles, or surfaces, facilitating the preparation of well-defined molecular constructs.

N-(Boc-PEG1)-N-bis(PEG2-propargyl) has found application in the preparation of multivalent or multifunctional biomolecules. The compound allows for the introduction of two payloads via its propargyl groups while maintaining the option to activate the central Boc-protected amine. This makes it particularly useful in the synthesis of heterobifunctional linkers, dendritic scaffolds, or modular therapeutic conjugates. In biomedical research, these properties support the development of antibody-drug conjugates, PEGylated proteins, and diagnostic probes with precisely controlled valency and orientation.

In materials science, such a compound can be incorporated into the design of hydrogels and surface coatings that require spatially defined attachment points and hydrophilic properties. The PEG chains enhance biocompatibility and resistance to nonspecific protein adsorption, while the terminal alkynes enable covalent crosslinking or functionalization with azide-containing polymers, peptides, or small molecules.

The structural architecture of N-(Boc-PEG1)-N-bis(PEG2-propargyl) also permits use in solid-phase synthesis and surface immobilization strategies. The Boc protection allows selective manipulation of the amine functionality, which may be used for anchoring onto solid supports or resin beads in combinatorial synthesis. Following deprotection, the amine may react with activated esters, isocyanates, or electrophilic centers, while the propargyl termini serve independently for conjugation or polymerization.

This compound is generally handled under standard laboratory conditions with attention to the sensitivity of its functional groups. The Boc group is stable under basic and neutral conditions but is cleaved by acids such as trifluoroacetic acid (TFA). The propargyl groups should be protected from oxidative or uncontrolled polymerization processes and are typically used in inert or controlled environments during CuAAC reactions.

Overall, N-(Boc-PEG1)-N-bis(PEG2-propargyl) exemplifies a class of custom-designed multifunctional PEG reagents that integrate solubility, selective reactivity, and synthetic flexibility. Its utility has been well-documented in fields such as bioconjugation, materials modification, drug delivery system design, and advanced organic synthesis.