Chapter 13

A lead compound containing a methyl ester was hydrolysed to give a carboxylic acid. An in vivo bioassay suggested that the ester was active and the acid was inactive. However, an in vitro bioassay suggested that the ester was inactive and the acid was active. Explain these contradictory results.

Procaine ( Box 13.2 ) has been a highly successful local anaesthetic and yet there are three bonds between the important ester and amine binding groups, compared with four in cocaine. This might suggest that these groups are too close together in procaine. In fact, this is not the case. Suggest why not.