PoraPak Rxn Brochure
8Pages

Post Synthesis Cleanup For post synthesis cleanup THE SCIENCE OF WHAT'S POSSIBLE.™

Waters now offers PoraPak™ Rxn, a family of polymer-based chromatography products for superior cleanup of synthetic reactions. PoraPak Rxn products are available in two chemistries: n PoraPak Rxn CX, a strong cation-exchange sorbent PoraPak Rxn RP, a reversed-phase sorbent. PoraPak Rxn sorbents are available in fritted syringe-barrel devices in 6, 20 and 60 cc volumes. The resins are also sold in bulk units, and custom configurations are available on request. Some Medicinal Chemists are familiar with silica-based chromatographic products for reaction cleanup. One of the limitations of these...

C LEANU P CHALLENGES Challenge Solution Load reaction mix on PoraPak Rxn CX cartridge and pass through high boiling point solvent such as DMSO. Convert or remove high boiling solvent before next reaction step - product is a base. Wash with methanol. Elute using 5% ammoniated methanol. Achieve sample enrichment and save time by evaporative removal of a low boiling point solvent before the next step. Separate product (bases) from reactants and reaction solvent. Remove TFA used in the reaction from bases. Load on PoraPak Rxn CX cartridge using a catch-and-elute strategy. Wash with methanol,...

[ REACTION CLEANUP ] CHOOSE T HE BEST P RODUC T AND T ECHNIQUE FOR YOUR CLEANU P PoraPak Rxn products are available in two sorbents: CX, a strong Cation-eXchange resin and RP, a Reversed-Phase resin. The illustrations below recommend the sorbent to use and the separation technique to apply during cleanup. The choice of the appropriate sorbent and technique depends upon the nature of the reaction products, reactants, solvents, and/ or preparative columns. Technique Reaction Products Recommended Product PoraPak Rxn CX Convert from high boiling point solvent for bases Pre-and-Post Preparative...

C LEANU P P ROC EDURES Using PoraPak Rxn CX: Strong Cation-Ion Exchange Catch-and-Elute and Pass-T hrough Protocols Pass Through Condition Step 100% methanol Condition with an organic solvent such as methanol. T his step is important to wet the sorbent. Condition Step 100% methanol Load Step Fraction collected contains acids, neutrals and reaction solvent Pour the reaction mixture into the cartridge. Let the reaction mixture flow by gravity. Load Step Fraction collected contains acids, neutrals and reaction solvent Wash Step 100%-methanol fraction contains more impurities, acids and...

C LEANU P OF A REDUC TIV E AMINATION MIX TURE Reductive amination is a common reaction carried out in medicinal chemistry laboratories. In this example, a PoraPak Rxn CX cartridge is used to fractionate the reaction mixture. Reaction Mixture Before Cleanup Crude reaction mixture. MBA, the starting amine, is present in small concentration with the product and an excess of the aldehyde. N-(Naphthylmethyl)methoxybenzylamine (product) Catch-and-Elute Procedure Condition Step 100% methanol Load Step Load Step Wash Step 100% methanol Collected fraction from the loading step. The fraction that...

P RODUC T GUIDELINES The following tables should be used as guidelines for loading capacity, flow rates, and volumes of wash and elution solvents. These tables take into consideration the dimension of the device and the bed volumes suggest appropriate flow rates and volumes for the condition, wash and elute steps. Maximum Capacity Guidelines Retained Compounds Retained Base The capacity is for the total of all compounds in the reaction that will be retained. For cation exchange, the capacity is for all bases in the reaction mixture including product and reactants. Consider smaller loads...

T he quality management system of Waters’ manufacturing facilities in Taunton, Massachusetts and Wexford, Ireland complies with the International Standard ISO 9001:2000 Quality Management and Quality Assurance Standards. Waters’ quality management system is periodically audited by the registering body to ensure compliance. ©2008 Waters Corporation. Waters, T he Science of W hat’s Possible ACQUITY, UPLC and PoraPak are trademarks of Waters Corporation. All rights reserved. 720002747EN 8/2008 IH-DS