TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: Acid is hydrochloric acid, sulfuric acid or phosphoric acid. The concentration of sodium methoxide solution is 20-30 wt.%. The mol ratio of acetamidine hydrochloride and sodium methoxide solution is 1:1-1.1.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: Solvent is water, methanol, ethanol or 4C saturated alcohol, preferably water or methanol. Alcohol solvent is methanol, ethanol or 4C saturated alcohol, preferably methanol or ethanol.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: Compound (II) is poly-2-aminostyrene, poly-4-amino-styrene, poly-3-aminostyrene, poly-3-(2-amino phenoxy)acrylic, poly-3-(3-amino phenoxy)acrylic, poly-3-(4-amino phenoxy)propyl, poly-2-(2-aminophenyl)ethanol acrylate, poly-2-(3-aminophenyl)ethanol acrylate, poly-2-(4-aminophenyl)ethanol acrylate, poly-4-aminopyridine-2-ethanol acrylate, poly-4-aminopyridine-4-ethanol acrylate, poly-3-amino-4-vinyl, poly-4-amino-3-vinyl, poly-4-amino-2-vinyl, poly-3-amino-2-vinyl, poly-4-amino-5-ethylene aminomethyl or poly-2-methyl-4-amino-5-ethylene aminomethyl. Preferred Method: 2-Methyl-4-amino-5-aminomethyl pyridine is prepared by: dissolving HC(=O)NHCH2CH(CH2CHOM)CN alkali alcohol into water to obtain polyvinyl alcohol aqueous solution; mixing solvent and compound (II), adding acid, and incubating at 0-100 degrees C for 30-40 minutes; adding polyvinyl alcohol aqueous solution, incubating to 0-100 degrees C, cooling to 0 degrees C, filtering, water washing, and drying to obtain enamine polymer; mixing acetamidine hydrochloride and sodium methoxide solution at 0-40 degrees C, and filtering; adding enamine polymer, alcohol solvent and benzene methyl ether, stirring at 80 degrees C, preferably 30-50 degrees C; and gas phase detecting, adding water, heating, cooling to room temperature, filtering, water washing to neutral, filtering, recovering, adding sodium hydroxide aqueous solution at 80-100 degrees C, and detecting.