Description

Amberlyst(R) A-21 is a macroreticular, strongly basic anion exchange resin supplied in the free base form. This versatile polymeric catalyst is valued for its high catalytic activity, excellent physical stability, and ease of separation from reaction mixtures. It is widely utilized in the chemical and pharmaceutical industries for catalyzing a range of organic transformations, including alkylations, condensations, and esterifications, where its heterogeneous nature simplifies downstream processing.

Application

• Catalyst for Organic Synthesis: Employed as a heterogeneous catalyst for reactions such as Knoevenagel condensations, Michael additions, and aldol condensations.
• Pharmaceutical Intermediate Production: Used in the synthesis of active pharmaceutical ingredients (APIs) and fine chemicals, facilitating cleaner processes.
• Esterification and Transesterification: Catalyzes the formation of esters from acids and alcohols, as well as the exchange of ester groups.
• Purification Processes: Acts as an adsorbent or scavenger to remove acidic impurities or catalysts from process streams.
• Alkylation Reactions: Facilitates C-, N-, and O-alkylation processes under mild conditions.
• Dehydrohalogenation: Used to promote elimination reactions for olefin synthesis.
• Polymer-Supported Reagent: Serves as a solid support for reagents in combinatorial chemistry and multi-step synthesis.

Basic Information

Product Name	Amberlyst(R) A-21
CAS No.	9049-93-8
Molecular Formula	(C6H5CH2N(CH3)3Cl)n (Base polymer structure)
Molecular Weight	N/A (Polymeric material)
Synonyms	Amberlyst A21; Amberlyst A-21 Ion Exchange Resin; Poly(styrene-co-divinylbenzene), chloromethylated, aminated; Strongly Basic Anion Exchange Resin Type I; Macroreticular Anion Exchange Resin; Dowex Type 1 Resin (analogous); Quaternary Ammonium Polystyrene Resin; Polymer-supported Trimethylbenzylammonium Chloride
EINECS	Contact for details

Quality Control

Our Amberlyst(R) A-21 is manufactured under controlled conditions to ensure batch-to-batch consistency and performance. Each lot undergoes rigorous quality testing to verify key parameters such as ion exchange capacity, moisture content, and particle size distribution. Certificates of Analysis (COA) documenting these specifications are available upon request.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at room temperature (15-25°C). Keep away from strong acids and oxidizing agents. The resin is moisture-sensitive; ensure the container is sealed after use to prevent absorption of atmospheric water and carbon dioxide, which can reduce catalytic activity.

Specification

Item	Specification
Appearance	Opaque, off-white to yellow spherical beads
Ionic Form (as shipped)	Free Base
Total Exchange Capacity	≥ 4.8 meq/g (dry)
Moisture Content	50 - 60 %
Particle Size Range	300 - 1200 µm
Uniformity Coefficient	≤ 1.7
Maximum Operating Temperature	60 °C (OH form)
Specific Gravity	1.06 - 1.08

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.