摘要 |
<p>A compound of formula (I) or a pharmaceutically acceptable salt thereof: <CHEM> wherein R1 represents <CHEM> in which each of p and q independently represents an integer of 2 to 4, r represents an integer of 2 to 4, s represents 1 or 2 and t represents 0 or 1; R2 is a group OR4, where R4 is C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, a group OCOR5 where R5 is hydrogen or R4, or a group NHR6 or NR7R8 where R6, R7 and R8 are independently C1-2 alkyl; and R3 is chloro, fluoro, bromo, cyclopropyl, C1-3 alkyl substituted by one, two or three halogen atoms, or R3 is a group (CH2)nR9 where R9 is -CN, -OH, -OCH3, -SH, -SCH3, -C IDENTICAL CH or -CH=CH2 and n is 0 or 1, with the proviso that when n is 0, R9 is not -OH or -SH.</p> |