Dihydropyrimidine compound and application in medicine

The invention relates to a dihydropyrimidine compound and an application of the dihydropyrimidine compound as a medicine, particularly to an application of the dihydropyrimidine compound as a medicinefor treating and preventing hepatitis B, specifically to a compound represented by a general formula (I) or (Ia) or a stereoisomer, a tautomer, a nitrogen oxide, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof, wherein each variable is defined in the specification. The invention also relates to application of the compound represented by the general formula (I) or(Ia) or the stereoisomer, tautomer, nitrogen oxide, solvate, metabolite and pharmaceutically acceptable salt thereof as a medicine, particularly to application of the compound as a medicine for treating and preventing hepatitis B. 本发明涉及一种二氢嘧啶类化合物及其作为药物的应用，尤其是作为治疗和预防乙型肝炎的药物的应用。具体地说，本发明涉及通式(I)或(Ia)所示的化合物或其立体异构体、互变异构体、氮氧化物、溶剂化物、代谢产物、药学上可接受的盐或它的前药，其中各变量如说明书所定义。本发明还涉及通式(I)或(Ia)所示的化合物或其立体异构体、互变异构体、氮氧化物、溶剂化物、代谢产物、药学上可接受的盐作为药物的用途，