TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The method for synthesizing 2-pyridin-3-yl-acetimidic acid methyl ester involves adding pyridin-3-yl-acetonitrile (10 g, 0.085 mol) to 250 ml single-mouth round bottomed flask, mixing with 30 ml methanol and reducing the temperature to -15 degrees C for 20 minutes. Hydrochloric acid gas is blown, and temperature is controlled at -10 degrees C, stirred for 12 hours, and reduced pressure distillation is performed to obtain 2-pyridin-3-yl-acetimidic acid methyl ester. The method for synthesizing 3-(2,2,2-trimethoxy-ethyl)-pyridine further involves adding 2-Pyridin-3-yl-acetimidic acid methyl ester (11.25 g, 0.075 mol) to a microwave reactor, adding 20 ml methanol, reacting at100 degrees C for 3 hours, filtering the solution and carrying out reduced pressure distillation to obtain 3-(2,2,2-Trimethoxy-ethyl)-pyridine. The method for synthesizing (1-(dimethoxy-phosphoryl)-1-hydroxy-2-pyridin-3-yl-ethyl)-phosphonic acid dimethyl ester further involves adding 3-(2,2,2-Trimethoxy-ethyl)-pyridine (9.8 g, 0.05 mol) to a 500 ml single-mouth flask, mixing with methylbenzene (200 ml) and reacted at90 degrees C, adding phosphorus trichloride (3 g, 0.07 mol) drop wise for 1 hour by stirring and cooling to 0 degrees C to eliminate the methylbenzene. 300 ml water is added to the solution and reflowed for 2 hours, filtered, and hot ethanol (300 ml) is added to filtrate, stirred, cooled, washed with water and ethanol, crystallized and dried to obtain white crystal (1-(dimethoxy-phosphoryl)-1-hydroxy-2-pyridin-3-yl-ethyl)-phosphonic acid dimethyl ester. The method for synthesizing (1-hydroxy-1-phosphono-2-pyridin-3-yl-ethyl)-phosphonic acid further involves adding (1-(dimethoxy-phosphoryl)-1-hydroxy-2-pyridin-3-yl-ethyl)-phosphonic acid dimethyl ester (9.69 g, 0.03 mol) to the single-mouth flask, mixing with 200 ml purified water, heating to 60 degrees C, stirring and slowly adding 15ml sodium hydroxide solution with concentration of 2 mol/L drop by drop to the mixture, filtering the solution, cooling, crystallizing, filtering and drying to obtain white crystal that is sodium risedronate.