The invention provides novel 2-adamantyl hydrazine derivatives of the general formula A

In this formula R, is hydrogen or a lower alkyl group of 1-4 carbon atoms; R 2 and R 3 are the same or different and are each hydrogen, an unsubstituted or substituted radical being a lower alkyl of 1-4 carbon atoms, a lower alkanoic acid radical of 2-4 carbon atoms or a lower alkyl ester thereof, adamantyl, aryl, aralkyl, in which the alkyl moiety has from 1-4 carbon atoms or an unsubstituted or substituted heterocyclic radical of aromatic character; or R 2 and R 3 together with the nitrogen atom to which they are attached form an unsubstituted or substituted non-aromatic cyclic radical.
The invention further provides pharmaceutically acceptable acid addition salts of the above compounds.
Several methods of preparation of the new compounds are described.
The novel compounds according to the invention possess valuable antifungal (human and plant), antiviral, antiprotozoal and antimicrobial properties.