NOVELTY - Synthesizing telaprevir intermediate, involves (a) mixing e.g. formic acid and catalyst, concentrating product, and performing distillation to obtain intermediate B, (b) mixing ammonium formate solution and intermediate B, adding Pichia yeast extract solution, stirring added materials, and obtaining intermediate C, and (c) adding cyclopropanamine and the intermediate C to reaction flask, heating the reaction flask, concentrating product, adding e.g. hydrogen chloride solution to concentrate, filtering product, and recrystallizing filter cake.    USE - The method is useful for synthesizing telaprevir intermediate (claimed).    ADVANTAGE - The method is cost-effective, environmentally-friendly, simple and suitable for large-scale production, and provides intermediate having high purity and high yield.    DETAILED DESCRIPTION - Method for synthesizing telaprevir intermediate, involves (a) mixing formic acid, ethyl butyrylacetate, catalyst and oxidizing agent at 15-20 degrees C, maintaining 15-20 degrees C for predetermined time, concentrating obtained product, and performing vacuum distillation of concentrate to obtain intermediate B, (b) mixing ammonium formate solution and the intermediate B, adjusting pH of obtained solution to 8, then adding mixture of nicotinamide adenine dinucleotide and dithiothreitol to the solution, adding Pichia yeast extract solution to obtained mixture, stirring added materials at 35-40 degrees C to obtain mixture having pH of 8, reacting the materials, adjusting pH of reacted product to 10, and allowing product to stand at 0-5 degrees C to obtain intermediate C, and (c) adding cyclopropanamine and the intermediate C to reaction flask, heating the reaction flask to 65-75 degrees C for 5-7 hours, cooling obtained product after reaction is completed, concentrating cooled product, adding hydrogen chloride solution and ethyl acetate solution to concentrate, stirring the materials, filtering stirred product, collecting filter cake, and recrystallizing the filter cake to obtain (S)-3-amino-N-cyclopropyl-2-hydroxyhexanamide hydrochloride. The intermediate B is represented by formula (I). The intermediate C is represented by formula (II).