Novel method for preparing tenofovir

The invention relates to a novel method for preparing tenofovir, in particular to a method for preparing a tenofovir compound, in particular the monohydrate of the tenofovir for resisting hepatitis B viruses and human immunodeficiency viruses. The method comprises the following steps of: using (substituted) triphenylchloromethane XIII to protect hydroxy in the end position of (R)-1,2-propanediol,condensing the obtained product with dialkyl sulfonyloxy methyl phosphonate V to obtain XV, hydrolyzing the XV in the aqueous solution of an organic acid to remove the protective group of the hydroxyl at the end position of XV to obtain an intermediate XI, condensing sulfonate XII of the intermediate XI with adenine to obtain an intermediate VII, transforming the intermediate VII into the corresponding trimethylsilyl phosphonate VIII by trimethylsilyl bromide (TMSBr), and hydrolyzing the VIII to obtain the target product. The method has the advantages of short process route, convenient operation, low cost and easy acc