Biotage® MP-TsOH
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Biotage MP-TsOH | Page 1 ® Resin-bound Acid Key Facts Shelf Life Capacity (mmol/g) Specifications Chemical Name: Macroporous polystyrene sulfonic acid (0.5% inorganic antistatic agent) Resin Type: Macroporous poly(styrene-codivinylbenzene) Scavenging and catch-and-release of amines, acid catalysis Scavenging Conditions: Approx. 2–3 equivalents of resin relative to amine, 0.5–1 h, 20 ˚C Compatible Solvents: MP-TsOH resin is a sulfonated macroporous polystyrene resin that is a resin-bound equivalent of p-toluenesulfonic acid (TsOH). The resin may be used as an equivalent to the strong cation-exchange resin, Amberlyst A-15 (Rohm and Haas).1–4 MP-TsOH has been optimized for use as a bound reagent or scavenger resin for the synthesis of small molecules. The sulfonic acid groups in MP-TsOH are readily accessible for removal of basic compounds (e.g. primary, secondary, and tertiary amines) by quartenary salt formation. In addition, MP-TsOH does not contain dark leachable impurities derived from over-oxidation of the polystyrene backbone observed in higher loading sulfonic acid resins.5 Thermally & Mechanically Stable Good Laboratory Practice Representative amine scavenging examples in batch as a function of time are provided in Table 1. MP-TsOH provides a useful alternative to quenching reactions with aqueous or soluble organic acids. Other Applications In Mitsunobu, Suzuki and Heck reactions, it is often challenging to isolate pure products from the byproducts such as triphenylphosphine oxide and palladium. MP-TsOH columns can be used to purify these products when they contain a basic functional group. The reaction mixture is applied to the column and the product is retained by MP-TsOH. The byproducts can be easily removed with a methanol or DCM wash step. The product can then be released by eluting with 2 M ammonia in methanol. MP-TsOH may also be used in cartridge applications to perform Catch-and-Release of amine derivatives in analogy to silica-derived SCX columns.6–8 Catch-and-Release Purification of Amines The procedure for isolating amines using MP-TsOH in columns is known as catch-and-release and is detailed below. When a solution containing an amine is passed through a MP-TsOH column the amine is retained or “caught” by the resin. Non-basic impurities are not retained and are further removed by washing the column with an organic solvent, such as DCM, THF or methanol. The product is subsequently “released” from the column by elution with a solution of ammonia in methanol. Amine salts of weak conjugate acids (e.g. acetate and trifluoroacetate) are exchanged onto the resin and are released as the free amine during

Biotage® MP-TsOH | Page 2 Pre-condition column Catch-and-Release Procedure 1. Column Pre-conditioning Wash the column with DCM, methanol or THF (4 mL/g resin). 2. Sample Loading Load the amine sample or reaction mixture onto column under gravity and discard the eluent. 3. Wash Impurity Remove the non-basic impurities by washing with DCM (3 x 3 mL/g resin). Discard the wash. 4. Amine Elution Elute basic amines with a solution of ammonia in methanol (2 M, 4 mL/g resin). Evaluate the use of 4 M ammonia/methanol solution (2 mL/g resin) to improve elution efficiency and reduce elution volume....

Biotage' MP-TsOH | Page 3 Ordering Information Part Number Quantity 1. Flynn, D. L.; Crich, J. Z.; Devraj, R. V.; Hockerman, S. L.; Parlow, J. J.; South, M. S. Woodard, S. S. J. Am. Chem. Soc. 1997, 119, 4874. 2. Gayo, L. M.; Suto, M. J. Tetrahedron Lett. 1997, 38, 513. 3. Parlow, J. J.; Flynn, D. L. Tetrahedron 1998, 54, 4013. 4. Suto, M. J.; Gayo-Fung, L. M.; Palanki, M. S. S.; Sullivan, R. Tetrahedron 1998, 54, 4141. 5. Stahlbush, J. R.; Strom, R. M.; Byers, R. G.; Henry, J. B.; Skelly, N. E. Prediction and Identification of Leachables from Cation Exchange Resins, Presented at the 48th...