| abstract |
Compounds of the formula (1) wherein R is aryl, substituted aryl, aralkyle or a hetero ring; R1 hydrogen or alkyl of 1-4 carbon atoms: A a saturated or unsaturated aliphastic hydrocarbon chain straight or branched in: R2 and R3 are the same or different and hydrogen, straight or branched or cyclic, saturated or unsaturated alkyl, aryl, substituted aryl or together with the nitrogen atom to which they are attached, and together with Y form a ring, in which Y is a methylene group or a heteroatom, the latter in the form of nitrogen, oxygen or sulfur: R4 hydrogen or linear or branched alkyl: X halogen or represent an organic or an inorganic anion, and n is 0,1,2 or 3 or in the case of a bi-acidic acid, n is equal to 0,5, 1,5 or 2,5: as well as their enantiomers and diastereoisomers. |