| abstract |
The process for the preparation of phenethanolamine derivatives of the general formula (I): wherein R 1 represents a hydrogen or fluorine atom, R 2 represents a methyl or ethyl radical, R 3 represents a hydroxy group or an alkanoyloxy radical with 1 4 carbon atoms, aminocarbonyl, methylaminocarbonyl or alkoxycarbonyl with 1 to 2 carbon atoms in the askoxy group C represents an asymmetric carbon atom having the absolute stereochemical configuration R and C represents an asymmetric carbon atom bearing the absolute stereochemical configuration S, namely a compound of the general formula II wherein R 1, R 2, R 3 have the abovementioned meanings, M represents a trimethylsilyl group is subjected to a hydrolysis reaction at a temperature between 0 and 50 ° C in methanol, at a pH of between 2 and 8, and optionally separating the product of formula U as a mixture of R, S and S enantiomers to obtain pharmacologically acceptable salts. |