TECHNOLOGY FOCUS - PHARMACEUTICALS - Preferred Process: The step (a) comprises adding 0.6 l of (II) and 68.9 g of zinc under a nitrogen atmosphere, reducing the temperature to -40 degrees C, then adding 24 ml of dibromomethane, stirring the mixture at 5 degrees C, adding 24 ml of titanium tetrachloride, increasing the temperature to 5 degrees C, keeping the reaction temperature for 4 days, and reacting the mixture to obtain (III). The step (b) comprises adding 40 g of (IV) and 400 ml of anhydrous chloroform into a reactor under the protection of nitrogen, then adding 2 g of lithium, 27 g of 4-dimethylaminopyridine and 16 ml of triethanolamine, stirring the mixture at 20 degrees C for 24 hours, adding 13.8 g of (V), reacting the mixture and performing a silica gel column chromatography to obtain (VI). The step (c) comprises adding 0.6 l of dichloromethane and 30 g of (VI) into a reaction tank under nitrogen atmosphere, then adding 0.6 l of (III), stirring the mixture at room temperature for 5 hours, mixing the reaction liquid with 1.3 l of a solution of saturated sodium bicarbonate and chloroform, stirring for 30 minutes, centrifuging, separating, extracting using 0.41 l of chloroform for three times, and performing column chromatography to (VII). The step (d) comprises: adding 190 ml of tetrahydrofuran, 190 ml of methanol and 18.9 g of (VII) into a reaction bottle, stirring, adding 3 mol/l of hydrochloric acid, heating at 50 degrees C, cooling to room temperature after the reaction, adding sodium hydroxide to adjust a pH value of 7, extracting using 300 ml of ethyl acetate for 3 times, filtering, rotary steaming to remove the solvent to obtain residue, and using diethyl ether to obtain (VIII). The step (e) comprises adding 6.9 g of (VIII) and 207 ml of dichloromethane into the reaction tank under a nitrogen atmosphere, stirring and reducing the temperature to 80 degrees C, adding 138 ml of a solution of 1.2 mol/l boron trichloride and dichloromethane, increasing the temperature to 40 degrees C, then reacting for 3 hours, adding 1.04 l of methanol, rotary steaming to remove the solvent to obtain entecavir crude product, and refining to obtain (I). (I) is in anhydrous form or crystal form. ACTIVITY - Antiinflammatory; Hepatotropic; Virucide.