Novel sulfone amide derivatives capable of inhibiting bace

Provided are a novel sulfone amide derivative having beta-secretase(BACE) inhibiting efficacy, a process for the preparation thereof, a BACE inhibitor composition containing the same as an active ingredient and a method for treating or preventing a disease caused by the generation of beta-amyloid by using the same. The sulfone amide derivative is represented by the formula 1, wherein A is a group substituted on a benzene ring, such as hydrogen, a halogen, cyano, nitro, a substituted or non-substituted alkyl, ester, amide, amine or alkoxy group; each of R1 and R2 is a simple alkyl group(-SAC), an allyl-containing, double bond-substituted alkyl group, a cycloalkyl group(-SCAC), an aromatic group(-Ar), an aromatic-substituted alkyl group(-SAC-Ar) or hydrogen, and R1 and R2 may form a ring with simple alkyl groups; R3 is -SAC, an allyl-containing, double bond-substituted alkyl group, -SCAC, -Ar, -SAC-Ar or hydrogen and contains a side chain residue from all of natural amino acids; and X is any substituent of the formulae 2 to 4.