m-PEG5-CH2COOH CAS 16142-03-3

Aure Chemical Supplies m-PEG5-CH2COOH CAS 16142-03-3 for PEG Linker and Specialty Synthesis

m-PEG5-CH2COOH, also known as methoxy-PEG5-carboxylic acid or CH3O-PEG4-CH2COOH, is a monofunctional PEG derivative featuring a methoxy end group and a terminal carboxylic acid. This structure supports selective modification at the acid end while the methoxy group remains inert, making it useful for controlled PEGylation. Aure Chemical provides sourcing support for this functional PEG derivative to customers engaged in pharmaceutical intermediate development and specialty synthesis projects.

The carboxylic acid group enables efficient coupling to amines or alcohols, while the longer PEG4 spacer adds hydrophilicity and flexibility. It is typically supplied as a liquid or low-viscosity oil with purity in the 95% to 99%+ range. This compound serves as a practical building block for researchers requiring a one-sided PEG carboxylic acid in conjugation chemistry and process development.

Basic Information

CAS No.	16142-03-3
EC No.	Not available
Linear Formula	CH₃O(CH₂CH₂O)₄CH₂COOH
Molecular Weight	266.29 g/mol
Appearance	Colorless to pale yellow liquid or oil
Melting Point	Not available (typical reference)
Boiling point	Not available (typical reference)
Density	~1.12 g/mL at 20 °C (lit.)
Solubility	Soluble in water and polar organic solvents
Storage Conditions	Keep in a tightly closed container in a cool, dry and well-ventilated place. Protect from moisture and incompatible materials.
Chemical Structure

Key Applications

• PEG linker intermediate: The methoxy-terminated PEG4 chain with carboxylic acid end group serves as a monofunctional hydrophilic spacer for selective conjugation in bioconjugation workflows.

• Molecular linker intermediate: Functions as a building block for introducing a PEG carboxylic acid moiety into organic molecules during fine chemical synthesis.

• Bioconjugation research: Enables PEGylation of amines on proteins, peptides, or surfaces through amide bond formation using the terminal carboxylic acid group.

• Fine chemical intermediate: Applied in the preparation of specialty compounds where a methoxy-PEG carboxylic acid unit improves solubility and provides a conjugation handle.

• Process development: Supports route optimization and custom synthesis of PEGylated materials for pharmaceutical research and development projects.

Why Work with Aure Chemical for m-PEG5-CH2COOH

• Consistent product quality: High-purity material with reliable batch consistency suitable for fine chemical synthesis and research applications.

• Flexible global supply: Support for laboratory, pilot-scale, and bulk quantities through established international logistics channels.

• SDS and COA support: Comprehensive product documentation including SDS and COA available to facilitate quality review and procurement processes.

• Packaging and technical service: Responsive technical communication and assistance with packaging options based on order requirements and product form.

Packaging and Storage

• Packaging: Available in small quantity sample bottles, 1 L to 25 L HDPE drums, and customized liquid packaging upon request.

• Storage: Store in tightly closed containers in a cool, dry, and well-ventilated area, protected from moisture and incompatible substances.

• Handling of opened containers: Minimize exposure to air and moisture after opening; reseal promptly and use contents within recommended timeframes.

• Bulk supply: Flexible packaging and delivery arrangements available for pilot-scale and commercial bulk orders.

Safety and Handling

• General handling: Follow good industrial hygiene and safety practices. Avoid unnecessary contact with skin, eyes, and clothing during handling and processing.

• Personal protection: Wear appropriate personal protective equipment including chemical-resistant gloves, safety goggles, and protective clothing as required.

• Documentation review: Always consult the latest Safety Data Sheet before handling, storage, transportation, or use of the material.

• Compatibility: Review compatibility with other process materials and avoid strong bases or conditions that may affect the carboxylic acid functionality.