Patent ID: 6875774

Claim:
A compound of formula I wherein R 1 is selected from the group consisting of hydroxy and alkoxy; R 2 is selected from the group consisting of ketone, aldehyde, ester and carboxylic acid; R 3 is selected from the group consisting of hydrogen, alkyloxyalkyl, alkylaminoalkyl, dialkylaminoalkyl and alkoxy unsubstituted or substituted; R 4 is selected from the group consisting of hydrogen, alkyloxyalkyl, alkylaminoalkyl, dialkylaminoalkyl and alkoxy unsubstituted or substituted; R 5 to R 8 are hydrogen; R 9 is selected from the group consisting of hydrogen, alkyl and alkylaryl, unsubstituted or substituted; and wherein one and only one of R 3 and R 4 is hydrogen.