Removing residual metals from post reactions can be a major issue. The toxic nature of transition -metals has led to the reduction of tolerated residual concentration in active pharmaceutical ingre-dients (APIs) to single digit ppm. However, many important key steps, such as coupling reactions (Suzuki, Heck, Stille, Sonogashira, etc), ring closing metathesis (RCM), and hydrogenation, still require the use of metal catalysts.
Purification of the API from remaining metal by traditional methods (chromatography, activated -carbon, distillation, recrystallisation, ultrafiltration, or reverse osmosis) often leads to problems such as high costs, time consuming, low efficiency, and API losses. SiliCycle has developed an efficient alternative: SiliaBond® Metal Scavengers.
These scavengers are made with SiliCycle's high purity silica gel: SiliaFlash®, which does not suffer from polymers' shortcomings, (i.e.: limited choice of solvents, excessive -swelling, extensive washings, poor selectivity, and static charge).
SiliaBond Metal Scavengers have significantly improved the way APIs can be synthesized. Any metal containing catalyst can be used, even downstream, as there are efficient scavengers available for -metals such as Pd, Pt, Sn, Ru, Rh, Ni, Cr, etc. Treatment with Metal Scavengers will selectively reduce the metal concentration without affecting the API.