Phthalazinone derivative, and preparation method and use thereof

The present application relates to a phthalazinone derivative, and a preparation method and a use thereof. In particular, the present application relates to a compound of formula I, and a prodrug, a metabolite form, a pharmaceutically acceptable salt or an ester thereof, or isomers, hydrates, solvates or crystalline forms of the above-mentioned items, and a preparation method and use thereof. The compounds of the present application can significantly enhance the inhibitory effect on the proliferation of tumour cells; and can increase the stability of molecules in vivo and reduce the possibility of producing toxic metabolites; or can reduce the oxidative metabolic capability of compounds under the action of a P450 cytochrome enzyme system in vivo by reducing the structural modification of the phthalazinone compounds, and can improve the bioavailability.