The preparation of amino bile acid derivatives

Bile acid derivatives have been prepared by reaction of their mixed anhydrides with diaminoethane. The new compounds have side chains modified by amide bond formation which extends the side chain by two carbon atoms and terminates in a primary amino group. Important properties of the new compounds are their solubility in acid, and their ability to act as nucleophiles in the carbodiimide reaction or mixed anhydride reaction. The derivatives have been used to prepare high molar ratio immunogens with bovine serum albumin and to prepare 125I labelled ligands for radioimmunoassay.