kilomentor | 31 March, 2012 14:41
I have talked about a number of recyclable reagents, such as lasalocid, in the previous blog. The title compound to-day can be used either as a salt forming reagent or as an appendage or protecting group.
It has a structure containing three phenyl groups strung together, end to end, through their para positions with an n-pentyloxy cap at one terminal and a carboxylic acid function at the other. All three rings are therefore para disubstituted. This acid, after coupling with the echinocandin B macrocycle, gives a product with excellent pharmaceutical properties. The substructure compound, as an amide derivative, is part of the drug anidulafungin. Since this linkage would be broken during the drug’s metabolism and since the drug has been found to be safe, this would seem to establish that this acid component is fairly nontoxic to the human metabolism.
This compound is a high melting solid and would be predicted to give high melting salts and other covalent derivatives. For example, the esters and amides are more likely to be solids using this rather than other carboxyl functionalities. The rigidity of the carbon skeleton might be expected to cause it to have a significant steric effect even remote to the point of attachment with another substructure. The expense of this potential protecting group would be ameliorated because the acid could be easily recovered and recrystallized to a dependable purity for recycling. Its use might be particularly promising where the process intermediates are expected to be liquids, oils, or waxes, such as in prostaglandin synthesis.