Committed to preserving our shared environment – further details available on request.
Can be used in processes in compliance with cGMP standards.
Manufacture of consumables is accredited by the world renowned British Standards Institute.
Flexible supply chains, back up manufacturing and warehousing ensures supply risk reduction
Can be used in processes in compliance with GLP standards.
Products which are scaleable from lab or development to process scale.
Long to indefinite product shelf life, reduced process risk.
Supports pharma guidelines for reducing elemental impurities in APIs.
Further extractable information provided on request.
Raw materials certified free of materials of human or animal origin.
Chemical substances used in our manufacturing process do not require registration.
Able to withstand mechanical stirring and heating under normal reaction conditions.
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Biotage® MP-Isocyanate is a macroporous polystyrene-bound scavenger, for nucleophiles such as amines and alkoxides. Resin-bound scavengers are added after a reaction is complete in order to quench and react selectively with excess reactants and/or reaction by-products. The resulting resin-bound adducts are removed by simple filtration.
Electrophilic Scavenger Options
Biotage supplies two isocyanate based scavenger resins: PS-Isocyanate and MP-Isocyanate. The resin backbone in PS-Isocyanate consists of 1% cross-linked polystyrene-co-divinylbenzene. Nucleophiles to be scavenged gain access to the isocyanate sites by diffusion through the polystyrene gel.
The MP-base copolymer is a highly cross-linked a robust and low-swelling material, which makes it ideal for restricted volume environments. Its unique pore structure provides greater access to the reactive sites without the need for solvent swelling, resulting in faster reactions and higher recoveries. The abrasion-resistant matrix has better handling characteristics and reduced transfer losses. Both these scavengers can be applied to similar chemistries; the main criteria for differentiation are the intended solvent choice and the format preference.
Scavenging Amines using MP-Isocyanate and PS-Isocyanate in 1,2-Dichloroethane
This study compared the ability of PS-Isocyanate and MP-Isocyanate to scavenge four amines from solution in DCE. Three equivalents of scavenger were used relative to the amine. At ambient temperature, the scavenging rates correlated directly with amine nucleophilicity.
Both resins were able to scavenge piperidine and benzylamine from solution within 1 h. Scavenging of aniline took place more slowly, reaching only 60–63% completion within 1 h. At 60 ˚C, PS-Isocyanate scavenged aniline to 92% completion, while MP-Isocyanate removed it completely from solution within 1 h. Scavenging of the highly hindered 2-aminobenzophenone was slow with both scavengers, even at 60 ˚C.
Effect of Different Solvents on Scavenging: MP-Isocyanate / PS-Isocyanate
Scavenging in THF, which swells 1% cross-linked polystyrene, was compared with scavenging in acetonitrile and methyl tertbutyl ether (MTBE). Acetonitrile and MTBE are poor solvents for swelling 1% cross-linked polystyrene. MTBE was chosen as a method for other ethereal solvents commonly employed in organic synthesis.
Scavenging rates for both scavengers followed the order THF > Acetonitrile > MeOH > MTBE.
Benzyl amine was scavenged rapidly in THF reaching 93% and 98% completion within 2 h with PS-Isocyanate and MP-Isocyanate, respectively. MP-Isocyanate scavenged more rapidly and more completely in the three other solvents, demonstrating it to be the scavenger of choice in solvents that do not swell 1% cross linked polystyrene.
Reducing the amount of scavenger from 3.5 equivalents to 2 equivalents reduced the amount of benzyl amine scavenged within the given time. We recommend the use of 3.5 equivalents for complete scavenging, but there is much scope for further optimization, depending on the application.