| 摘要 |
Compounds of the formula I <CHEM> wherein R1 represents a hydrogen atom or a methyl group, either R2 and R3 represent hydrogen atoms or together represent a chemical bond, R4 represents a hydrogen atom or a C1-C4 alkyl group, R5 represents a C1-C4 alkyl group or an allyl group and R6 represents a hydrogen or halogen atom, and the pharmaceutically acceptable salt thereof, are useful for the manufacture of a pharmaceutical composition useful in the treatment of extrapyramidal syndromes such as Parkinson's disease. |
