123456123456A process for preparing aminoadamantyl carbamate derivatives useful as important intermediates for 11ßHSD 1 inhibitors is provided. A process for preparing acid addition salts of compounds represented by general formula (II) or solvates of the acid addition salts has been found said process being characterized by adding an acid to a mixture of syn and anti isomers of a compound represented by general formula (I) in the presence of a solvent and thereby separating an acid addition salt of a compound represented by general formula (II) or a solvate of the acid addition salt. In general formula (I) R and R are each independently hydrogen substituted or unsubstituted alkyl or the like R and R are each independently hydrogen substituted or unsubstituted alkyl or the like and R and R are each independently hydrogen halogen carboxy nitro substituted or unsubstituted alkyl or the like while in general formula (II) R R R R R and R are each as defined above.
