| abstract |
A process for preparing compounds with bronchodilator properties, of formula **(Formula-01)** and its therapeutically acceptable salts, in which formula n is 1, 2 or 3; R1 is selected from the group consisting of H, aliphatic acyl groups containing 2 to 4 carbon atoms, and unsubstituted benzoyl, of the formula **(Formula-02)** where R3 is selected from the group consisting of hydrogen and methyl ; and where R2 is selected from the group consisting of H, aliphatic alkyl groups containing 1-4 carbon atoms, benzyl, aliphatic acyl groups containing 2 to 5 carbon atoms, and unsubstituted or substituted benzoyl, of the formula **( Formula-03)** where R4 is selected from the group consisting of hydrogen and methyl; process comprising reacting a compound of formula **(Formula-04)** where R is hydrogen, an aliphatic group containing 2 to 5 carbon atoms, unsubstituted or substituted benzoyl, of formula **(Formula-05) ** where R3 is hydrogen or methyl, or a hydroxyl protecting group, such as an alkyl group containing 1-5 carbon atoms or a mono- or bicyclic aralkohyl group of not more than 11 carbon atoms, such as benzyl or naphthylmethyl, with a compound of formula **(Formula-06)** where n is 1, 2 or 3, R2 is selected from the group consisting of hydrogen, aliphatic alkyl groups containing 1-4 carbon atoms, benzyl, aliphatic acyl containing 2 to 5 carbon atoms, and unsubstituted or substituted benzoyl of the formula **(Formula-07)** where R4 is hydrogen or methyl, and where R5 is hydrogen or an N-protecting group, such as benzyl , until formation of a compound of formula **(Formula-08)** after which, if necessary, the prot groups are eliminated ectors R and R5; after which, if desired, the compound of formula I thus obtained is converted into its pharmaceutically acceptable salt and/or resolved into its optical isomers. |