摘要 |
A compound having the formula: <IMAGE> wherein R1 is halogen or a substituted or unsubstituted hydrocarbon group; R2+L, R6 and R7, which may be the same or different, each represents hydrogen or a substituted or unsubstituted hydrocarbon group, or R6 and R7 taken together may represent a hetero group having one or more hetero atoms; R3 and R4 which may be the same or different each represents a substituted or unsubstituted hydrocarbon group; or R3 and R4 taken together may represent an alkylene group or a hetero group having one or more hetero atoms and R5 is hydrogen, a substituted or unsubstituted hydrocarbon group, halogen or a free or protected hydroxy group, or a pharmaceutically acceptable salt thereof. The compounds have antiaggregating properties. |