Our more recent 5'-amino modifiers, protected by a novel phthalic acid diamide (PDA) protecting group, are stable solids. In contrast to the TFA protected amino modifiers, which are viscous oils, the analogous PDA protected compounds are granular powders. This important property of these compounds allows straightforward handling, storage and aliquoting and leads to a significant increase in stability.
Deprotection with methylamine in gas phase or aqueous solution or AMA leads to fast and complete removal of the PDA protecting group. However, ammonium hydroxide will not drive the equilibrium reaction to completion and only partial deprotection occurs - overnight deprotection with ammonium hydroxide will yield around 80% active amine.
We offer three PDA Amino-Modifiers:
|Diluent||25% DCM in Acetonitrile|
|Storage||Freezer storage, -10 to -30°C, dry|
The table below show pack size data and, for solutions, dilution and approximate coupling based on normal priming procedures.
|Catalog #||Pack Size||Grams/Pack||0.1M Dil. (mL)||Approximate Number of Additions|
|Catalog #||Pack Size||Grams/Pack||Dilution (mL)||Approximate Number of Additions|