Twenty derivatives bearing substituents on the phenolic function of (-)-3-(3-hydroxyphenyl)- N-propylpiperidine [(-)-3-PPP] were synthesized and tested as prodrugs. The carbamate ester derivatives were found to be the most suitable prodrugs, and especially the 4- isopropylphenylcarbamate 20 was capable of escaping the first-pass metabolism and still generating high plasma levels of the parent compound. Four hours after an oral dose of ...
