Patent ID: 7087596

Claim:
Compounds of the formula I wherein n is equal to 1; A 1 is an oxygen atom; X is —CONR 7 R 8 ; R 1 , R 2 and R 5 are hydrogen R 3 and R 4 are the same or different and each is independently hydrogen, ester of formula —CO—O—R 11 , alkyl optionally substituted by one or more substituents selected from halogen and hydroxy, alkenyl optionally substituted by one or more halogen, alkynyl optionally substituted by one or more halogen, or aryl optionally substituted by one or more halogen, provided that at least one of R 3 and R 4 is not hydrogen; R 6 is hydrogen or alkyl; R 7 and R 8 are the same or different and each is independently hydrogen or alkyl; R 11 is alkyl; and their pharmaceutically acceptable salts, geometrical isomers, enantiomers, diastereoisomers and mixtures thereof, and all possible mixtures of stereoisomers.