597861 Disclosed is an ester derivative of 2-amino-2-phenyl-alkanol of general formula I, such as 3,4,5-trimethoxy-benzoic acid 2-phenyl-azetidin-2-yl methyl ester, 3,4,5-trimethoxy-benzoic acid 5-methyl-2-phenyl-pyrrolidin-2-yl methyl ester, 3,4,5-trimethoxy-benzoic acid 6-methyl 2-phenyl-piperidin-2-yl methyl ester and 3,4,5-trimethoxy-benzoic acid 7-methyl-2-phenylazepan-2-yl methyl ester.