Preparation method of PI3K inhibitor

The invention provides a preparation method of a PI3K inhibitor. The PI3K inhibitor is (S)-2-[1-(9H-purine-6-ylamino) ethyl]-3-(dimethylamino)-5-fluoroquinazoline-4 (3H)-ketone, and the structural formula of the PI3K inhibitor is shown in the specification. The method comprises three steps of reactions. The method has the advantages of simple reaction steps, mild reaction conditions, indiscriminate application of the solvent, economy and environmental protection. The PI3K inhibitor is subjected to optical purification and salifying crystallization refining through organic acid resolution and has simplicity in operation, improved yield, low cost and more stable batch-to-batch quality in comparison with present silica gel column chromatography and preparation separation and is suitable for industrial production. 本发明提供一种PI3K抑制剂的(制备方法，所述PI3K抑制剂为(S)-2-[1-(9H-嘌呤-6-基氨基)乙基]-3-(二甲氨基)-5-氟喹唑啉-4(3H)-酮，该方法通过三步反应制备所得，反应步骤简单，反应条件温和，溶剂可套用，经济环保，本发明通过有机酸拆分进行光学纯化及成盐结晶的方式精制，较现有的硅胶柱层析和制备分离，操作简便，收率提高，成本低，批次间的品质更加稳定，适合工业生产。