| 摘要 |
Compounds of the formula (I) and pharmaceutically acceptable salts thereof: <IMAGE> (I) wherein: R1 is C1-6 alkyl; R2 is hydrogen or C1-7 acyl; R3 is C1-6 alkyl; R4 is a group CH2R5 wherein R5 is hydrogen, C3-8 cycloalkyl or phenyl optionally substituted by one or two substituents selected from C1-6 alkyl, C1-4 alkoxy, trifluoromethyl and halogen, having useful anti-emetic activity. |
