Benzoic acid derivatives are important due to their pharmaceutical and biological activities and their industrial applications. The main derivatives of benzoic acid are salicylic acid. This compound and its derivatives are antiseptic and antipruritic drugs, Hence one of the aims in this work is the synthesis and prepare the new derivatives of these compounds. In this work, we report the synthesis of several derivatives of methyl salycilate. Methyl-2,4-dimethoxy salicylate ( 29 ), methyl-3-(2,4,6-trimethoxy) benzoate (40) and bis(2,4,6-trimethoxy phenyl)methanone ( 41 ) by new method. The Friedel-crafts reaction of electronic rich 1,3,5-trimethoxy benzene (27) , aluminum chloride as catalyses and methyl chloroformate solvent with or without solvent and SiO 2 produced adducts in good yields. According to the resent advances in computational analysis promoted an investigation of intramolecular hydrogen bonding and conformational analysis of 29 and its derivatives ( 29b, 29c and 29d) by using the Hartree-Fock (HF) and density functional methods. The molecular structure and geometry of methyl-2,4-dimethoxysalicylate (29) with its derivatives ( 29b, 29c, 29d ), The FT-IR vibration frequencies, NBO values and 1 H, 13 C NMR spectra of compound 29 were calculated in CDCl 3 , methanol, DMSO-d 6 and in vacuo using were exactly considered.