An efficient synthesis of prasugrel, a novel P2Y12 receptor inhibitor, is described. The cyclopropyl-phenylethanone intermediate was prepared by cyanide substitution, bromination, N-substitution, and the Grignard reaction. After acid hydrolyzation of the methyl ether and subsequent acetylation, the title product was obtained with a total yield of 21% after 10 linear steps from simple and commercially available raw materials.