Patent ID: 6903129

Claim:
A compound of formula wherein R 1 and R 2 are independently from each other lower alkoxy, lower alkenyloxy, hydroxy, —OCH(CH 3 )OC(O)-lower alkyl or —OCH 2 C(O)N(R 3 )(R 4 ), with the proviso that only one of R 1 or R 2 may be hydroxy; R 3 and R 4 are independently from each other hydrogen, lower alkyl, lower alkenyl or cycloalkyl; or R 1 and R 2 form together with the carbon atom, to which they are attached the linking group X, wherein X is —O(CH 2 ) n CH═CH(CH 2 ) n O— or —O(CH 2 ) m O—; n is 1, 2 or 3; and m is 4-8; or a pharmaceutically acceptable salt thereof.