NOVELTY - Nevirapine is prepared by mixing 2-chloronicotinic acid, sodium bicarbonate aqueous solution and ethanol, then adding mixture into cyclopropylamine, raising temperature to 50 degrees C to react and obtain 2-cyclopropylamino nicotinic acid; reacting the 2-cyclopropylamino nicotinic acid with N-hydroxysuccinimide and dicyclohexylcarbodiimide in tetrahydrofuran, standing overnight, filtering, adding filtrate with triethylamine and 2-chloro-3-amino-4-methyl pyridine to prepare cyclopropylamino pyridine compound; and ring closing reacting cyclopropylamino pyridine compound with potassium tert-butoxide.    USE - Method of preparing nevirapine (claimed) used for treating HIV.    ADVANTAGE - The method utilizes easy to obtain raw material, and is simple in operation, low in pollution and suitable for industrial production.    DETAILED DESCRIPTION - Preparation of nevirapine comprises:    (A) mixing 2-chloronicotinic acid, sodium bicarbonate aqueous solution and ethanol, stirring for 30 minutes, then adding mixture into cyclopropylamine, raising temperature to 50 degrees C to react, after reaction, concentrating to recycle ethanol and cyclopropylamine, adding ethyl acetate to extract the residue, layering, cooling, then adding hydrochloric acid into the water layer to regulate pH value to 4-5, standing for 30 minutes, then filtering, washing the filter cake with water, and drying to obtain 2-cyclopropylamino nicotinic acid;    (B) adding the 2-cyclopropylamino nicotinic acid, N-hydroxysuccinimide and dicyclohexylcarbodiimide into tetrahydrofuran, stirring at room temperature, reacting and standing overnight, filtering to remove dicyclohexylurea, then adding triethylamine and 2-chloro-3-amino-4-methyl pyridine into the filtrate and reacting and standing overnight, after reacting, concentrating to remove tetrahydrofuran, dissolving the residue with ethyl acetate, then washing the ethyl acetate layer with 1 N hydrochloric acid, water, saturated sodium bicarbonate aqueous solution and saturated saline solution, then drying over anhydrous sodium sulfate, filtering, concentrating the filtrate, adding isopropyl ether for freezing and crystallizing the residue, filtering, washing the filter cake with cold isopropyl ether, and drying to prepare cyclopropylamino pyridine compound; and    (C) adding the cyclopropylamino pyridine compound and potassium tert-butoxide into dimethylbenzene and reflux reacting, after reacting, cooling the reaction solution, adding into deionized water, then dripping acetic acid, regulating pH value to 7-7.5, raising the temperature to 25 degrees C, stirring for 1 hour for crystallizing, filtering, washing the filter cake with cold deionized water, then adding the filter cake into mixed solvent of methanol and deionized water, raising the temperature to 65 degrees C, adding active carbon for decolorizing, filtering to remove active carbon, then washing the filter cake with hot methanol, concentrating the filtrate until reaching a certain volume, cooling and crystallizing, filtering, washing the filter cake with cold deionized water, and drying to prepare the nevirapine.