58 results about "Methylbenzoprim" patented technology

The invention provides a preparation method of telbivudine, wherein the method comprises the following steps: 1) adding thymine and hexamethyl disilylamine to an organic solvent, and carrying out a reaction, wherein the organic solvent comprises one of dimethyl sulfoxide, N,N-dimethylformamide, and N,N-diethyl formamide; 2) adding (2S,3R)-5-chloro-2-(((4-methyl benzoyl)oxo)methyl)tetrahydrofuran)-3-yl)-4-methyl benzoate, carrying out a reaction, adding an NaHCO3 solution, stirring and filtering, and carrying out reduced pressure concentration on the filtrate; and 3) adding an alcohol solvent, then adding sodium ethoxide, carrying out a reaction, adding cation exchange resin, and carrying out heat preservation stirring; and cooling and filtering, concentrating the filtrate until a solid is precipitated, and crystallizing, to obtain a telbivudine crude product. The adopted reagents and raw materials both have low toxicity; the method has the advantages of simple preparation process, mild reaction conditions, easy operation, stable physical and chemical properties of the raw materials, fewer by-products and high yield.