| abstract |
The present invention relates to compounds of formula I in the form of a pure optical or geometric isomer or mixture of isomers, wherein R 1 is C 1 -C 4 alkyl or C 3 -C 7 cycloalkylmethyl, X 1 is hydrogen or halogen or C 1 -C 4 alkoxy; and X 1 together are -OCH 2 O-, -O (CH 2) 2 -, -O (CH 2) 3 -, -O (CH 2) 2 O - or -O (CH 2) 3 O -, X 2 is hydrogen or amino, X 3 is hydrogen. or halogen, and R2 is hydrogen, (C1-C6) -alkyl or phenyl (C1-C4) -alkyl or - (CH2) nCO-Z wherein n is an integer from 1 to 6 and Z is piperidine; The free base or a pharmaceutically acceptable acid addition salt thereof. The compounds are useful in medicine. The invention also encompasses a process for the preparation of the compounds and pharmaceutical compositions containing the compounds. SHE |