Abstract: A process for the purification of clavulanic acid comprising reacting in an organic solvent impure clavulanic acid with a diamine of the formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are individually selected from the group consisting of alkyl of 1 to 8 carbon atoms, cycloalkyl of 3 to 8 carbon atoms and cycloalkyl alkyl of 3 to 8 cycloalkyl carbon atoms and alkyl of 1 to 8 carbon atoms, all optionally substituted with 1 to 3 members of the group consisting of halogen, --OH, lower alkoxy and carboxy esterified with lower alkyl or R.sub.1 and R.sub.2 or R.sub.3 and R.sub.4 taken with the nitrogen to which they are attached form piperidino and n is an integer from 1 to 10 to form an amine salt selected from the group consisting of ##STR2## recovering the amine salts and acidifying the amine salt to recover purified clavulanic acid.