Compound of formula I is hiv reverse transcriptase inhibitor, wherein R1, R2, RE, L, M and Z are as defined herein. The compound of Formulas I and their pharmaceutically acceptable salt can inhibit hiv reverse transcriptase with what, prevent and treat HIV infection, prevention AIDS, the breaking-out for postponing AIDS or development and treatment AIDS. The compound and their salt may be used as the component of pharmaceutical composition, optionally be combined with other antivirotics, immunomodulator, antibiotic or vaccine.式I化合物是HIV逆轉錄酶抑制劑，其中，R1、R2、RE、L、M和Z如本文所定義。式I的化合物和它們的藥學可接受的鹽可用於抑制HIV逆轉錄酶、預防和治療HIV感染、預防AIDS、延遲AIDS的發作或發展以及治療AIDS。所述化合物和它們的鹽可以用作藥物組合物的組分，任選與其它抗病毒劑、免疫調節劑、抗生素或疫苗聯用。
