The use of a compound of formula (I) or a salt, ester, amide or prodrug thereof where X is O, or S, S(O) or S(O)2, NH or NR12 where R12 is hydrogen or C1-6 alkyl R5 is selected from a group NHC(O)OR9, NHC(O)R9, NHS(O)2R9, C(O)R9, C(O)OR9, S(O)R9, S(O)OR9, S(O)2OR9, C(O)NR10 R11, S(O)NR10R11 S(O)ONR10R11, where R9, R10 or R11 are various specified organic groups R6 is hydrogen, optionally substituted hydrocarbyl or optionally substituted heterocyclyl R7 and R8 are various specified organic groups, and R1, R2, R3, R4 are independently selected from halogeno, cyano, nitro, C1-3alkylsulphanyl, &mdashN(OH)R13&mdash (wherein R7 is hydrogen, or C1-3alkyl), or R15X1&mdash (wherein X1 represents a direct bond, &mdashO&mdash, &mdashCH2&mdash, &mdashOCO&mdash, carbonyl, &mdashS&mdash, &mdashSO&mdash, &mdashSO2&mdash, &mdashNR16CO&mdash, &mdashCONR16&mdash, &mdashSO2NR16&mdash, &mdashNR17SO2&mdash or &mdashNR18&mdash (wherein R16, R17 and R18 each independently represents hydrogen, C1-3alkyl or C1-3alkoxy C2-3alkyl), and R9 is hydrogen, optionally substituted hydrocarbyl, optionally substituted heterocyclyl or optionally substituted alkoxy in the preparation of a medicament for use in the inhibition of aurora 2 kinase.
