| abstract |
A compound of the formula wherein R 1 is hydrogen or alkyl; R2 is -CR¿R¿-Ra (where R¿ and R¿ are hydrogen, hydroxyalkyl or alkyl being at least one alkyl or hydroxyalkyl and Ra is hydroxyalkyl), where each of the hydroxyl group present in R2 may independently be in the form of an ester, a carbamate, a carbonate or a sulphonate derivative; R3 is hydrogen, alkyl, amino, monoalkylamino, dialkylamino, cycloalkyl, aryl, aralkyl, haloalkyl, heteroalkyl, cyanoalkyl, C-alkylene (O) -R (where R is hydrogen, alkyl, hydroxyl, alkoxy, amino, monoalkylamino or dialkylamino) or acyl; Ar1 is aryl, does aryl mean a monovalent monocyclic or bicyclic aromatic hydrocarbon radical that is optionally substituted independently with one, two or three, substituents chosen from the group consisting of alkyl, hydroxyl, alkoxy, haloalkyl, haloalkoxy, heteroalkyl, halo, nitro, cyano, amino, monoalkylamino, dialkylamino, methylenedioxy, ethylenedioxy and acyl; "Acyl" means a radical -C (O) R, wherein R is hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, phenyl or phenylalkyl; "Heteroalkyl" means an alkyl radical as defined herein where one, two or three hydrogen atoms. |