Patent ID: 7271168

Claim:
A compound of formula I wherein X is a single bond or —O—, —S—, —CH 2 —, —CH═CH— or —CH 2 —CH 2 —, R 1 is (C 1-4 )alkyl, (C 2-5 )alkenyl or (C 3-7 )cycloalkyl(C 1-4 )alkyl, and R 2 is a group of formula wherein Y is —O— or —S—, R 3 and R 4 , independently, are hydrogen, hydroxy, halogen, nitro, cyano, trifluoromethyl, (C 1-4 )alkyl or (C 1-4 )alkoxy , and R 5 is hydrogen or (C 1-4 )alkyl, in free base or acid addition salt form.