TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The step (i) comprises adding methanol solution of (I) (15-17 wt.%) to the aqueous solution of cesium carbonate (15-17 wt.%) to obtain Boc-Pro-Cs solution of pH 7-7.5, vacuum concentrating in a water bath at 40-50 degrees C, evaporating solvent to obtain solid, adding methanol, vacuum evaporating, vacuum drying to a constant weight in a dryer comprising phosphorus pentoxide as a drying agent, adding the dried Boc-Pro-Cs to anhydrous dimethylformamide solvent, heating to 40-50 degrees C to dissolve, adding Boc-Pro-Cs to (II) (2.5-3 times of the wt. of the dried Boc-Pro), stirring at a constant temperature of 40-50 degrees C for 40-48 hours, reacting, filtering, washing resin, baking in an oven at 45-50 degrees C for 12-16 hours and vacuum drying in the drier (comprising phosphorus pentoxide as a drying agent) to a constant weight to obtain (I). The methanol added in step (i) is vacuum evaporated at least twice. The resin in step (i) is washed using anhydrous dimethylformamide and purified water until no chloride ions are remaining in the reaction, and washing using absolute ethanol and methanol, respectively. The raw material preparation comprises washing (I) (600 parts by wt.) using anhydrous dichloromethane, stirring and draining. The method for removing the blocking group comprises adding the prepared raw material to the hydrogen chloride/isopropyl alcohol solution (9-10 N) and dichloromethane mixture (in a volume ratio of 1:1), when connecting the dipeptide to the heptapeptide, shaking and draining, and adding the heptapeptide product to the hydrogen chloride/isopropyl alcohol solution (9-10 N), dichloromethane and mercaptoethanol (in a volume ratio of 10:9:1), when connecting octapeptide and nonapeptide, shaking and draining. The washing process comprises washing the blocking group removed product using dichloromethane, draining and washing using dimethylformamide and draining, when connecting the dipeptide to the nonapeptide. The neutralizing process comprises adding the washed product to the triethylamine/dichloromethane solution (in a volume ratio of 5:95), washing, stirring for 2 minutes and draining, when connecting dipeptide to nonapeptide. The repeatedly washing step comprises washing the neutralized product using dimethylformamide, draining and washing to neutral using dichloromethane and draining, The step of connecting peptide comprises dissolving connected peptide raw material in anhydrous dimethylformamide, pouring into (I) resin, plugging the bottle, stirring and draining the solvent, washing using dichloromethane, anhydrous ethanol and dimethylformamide, washing using dichloromethane and draining, when connecting dipeptide to nonapeptide. The free amino group is detected using Kaiser reagent. The washing process in step (ii) comprises washing the nonapeptide using dichloromethane, absolute ethanol and dimethylformamide, respectively, repeating washing using dichloromethane and methanol and draining, drying in an oven at 40-50 degrees C for at least 5 hours, and vacuum drying in the drier (comprising phosphorus pentoxide as a drying agent) to a constant weight to obtain leuprorelin acetate nonapeptide resin. The aminolysis process comprises adding leuprorelin acetate nonapeptide resin to absolute methanol, adding ethyl amine, sealing, shaking at normal temperature, draining the excess ethyl amine, filtering, washing the resin using methanol, vacuum concentrating, drying to obtain foamy first concentrate, dissolving the first concentrate in methanol, precipitating using acetone and filtering, dissolving the filter cake in acetic acid, vacuum concentrating, drying, adding methanol, concentrating and drying to obtain the foamy second concentrate, dissolving the second concentrate in methanol, precipitating using acetone and filtering, washing the filter cake in acetone and diethyl ether, draining, and vacuum drying to obtain leuprorelin acetate crude product. The purification process using HPLC comprises dissolving leuprorelin acetate crude product in sodium acetate solution, filtering, adjusting conductivity, sampling through chromatographic column, completing sampling, washing using sodium acetate buffer liquid until optical density is steady, eluting using sodium acetate buffer liquid, collecting eluate when peaks are obtained, completing collection until the optical density does not vary, filtering the collected eluate, sampling through HPLC preparation column, conducting gradient elution, collecting the main peak solution to obtain leuprorelin acetate intermediate purified product. The condensing process in step (v) comprises after diluting the leuprorelin acetate intermediate purified product by water injection, absorbing the purified product on HPLC preparation column, washing using ammonium acetate solution and acetic acid/acetonitrile solution, respectively and eluting using acetic acid/acetonitrile solution, collecting fractions having optical density, and vacuum concentrating to obtain leuprorelin acetate concentrate. The step (vi) comprises conveying leuprorelin acetate concentrate to a clean area to prepare solution, filtering through a membrane filter, and freeze-drying the filtrate in a freeze-drier to obtain leuprorelin acetate freeze-dried products. Preferred Components: The peptide connecting raw material comprises: a dipeptide connecting material comprising (in parts by wt.) N-(tert-butoxycarbonyl)-L-arginine hydrochloride (247.5), 1-hydroxybenzotriazole (139.9), and dicyclohexylcarbodiimide (213.21); a tripeptide connecting material comprising (in parts by wt.) N-(tert-butoxycarbonyl)-L-leucine monohydrate (225), 1-hydroxybenzotriazole (139.9) and dicyclohexylcarbodiimide (213.21); a tetrapeptide connecting material comprising (in parts by wt.) N-(tert-butoxycarbonyl)-D-leucine (207.8), 1-hydroxybenzotriazole (139.9) and dicyclohexylcarbodiimide (213.21); a pentapeptide connecting material comprising (in parts by wt.) N-(tert-butoxycarbonyl)-L-tyrosine (253.98), 1-hydroxybenzotriazole (139.9) and dicyclohexylcarbodiimide (213.21); a hexapeptide connecting material comprising (in parts by wt.) N-(tert-butoxycarbonyl)-L-serine-o- tert butyl (235.26), 1-hydroxybenzotriazole (139.9) and dicyclohexylcarbodiimide (213.21); a heptapeptide connecting material comprising (in parts by wt.) N-(tert-butoxycarbonyl)-L-tryptophan (273.6), 1-hydroxybenzotriazole (139.9) and dicyclohexylcarbodiimide (213.21); an octapeptide connecting material comprising (in parts by wt.) N-(tert-butoxycarbonyl)-L-histidine-tosyl (360), 1-hydroxybenzotriazole (139.9) and dicyclohexylcarbodiimide (213.21); and a nonapeptide connecting material comprising (in parts by wt.) pyroglutamic acid (115.5), 1-hydroxybenzotriazole (139.9) and dicyclohexylcarbodiimide (213.21). ACTIVITY - Endocrine-Gen; Gynecological; Cytostatic.