Moisture scavengers Molecular sieves

The intermediate phosphite employed in this synthesis was prepared by condensation of duly protected sialic acid with the nucleosidyl phospho-roamidite in the presence of N-PhIMT. Oxidation by TBHP and deprotection according to standard procedures gave the cytidine-S -monophospho-iST-ace-tylneuraminic acid. This synthetic route is claimed to have advantages over procedures published earlier [26]. The same group demonstrated the importance of 3 A and 4 A molecular sieves as moisture scavengers in the reaction of nucleoside phosphoroamidite with a nucleotide. This approach should be likely to find application in the synthesis of biophosphates outside nucleotide chemistry. 

Zeolites have found two major applications in polymeric systems as selective membranes and as in situ drying agents. In moisture sensitive systems such as polyurethanes and polysulfides, molecular sieves help to scavenge moisture which extends the shelf-life of moisture cured products manufactured from these polymers. In these applications, 3 A molecular sieves are safe to use without special precautions because they contain no gas in their pores. Larger pore size sieves should be added under the vacuum to remove gas from the pore volume. 

Molecular sieves are also used to scavenge moisture to prevent its condensation in insulated glass units. They are added to adhesive spacers or contained within the spacer which divides the glass panes. The spacer is a barrier to the penetration of the ambient atmosphere into the enclosed space of insulated glass unit. 

Molecular Sieve 3A, Moisture Scavenger 2.7 Disperse Using A Planetary Mixer. 

---