Compound as cyclin-dependent kinase 9 inhibitor and use thereof

Disclosed is a compound as shown in formula (I) or a pharmaceutically acceptable salt, a stereoisomer, an isotope derivative or a prodrug thereof. The compound has an excellent activity as a cyclin-dependent kinase 9 (CDK9) inhibitor for treating hyperprliferative diseases. The experimental research on in vitro inhibition of cell proliferation and in vivo suppression of tumors shows that such compounds have a relatively strong inhibitory effect on MV4;11 cells and in vivo tumor models, and have a good selectivity and a low toxicity and few side effects, thereby possessing a good clinical value as novel anti-tumor drugs.