A Novel Synthetic Method of 3-Methyleneisobenfuran- 1(3H)-one and Their Derivatives

Abstract

A novel and highly efficient synthesis of 3-methyleneisobenzofuran-1(3H)-one and the corresponding derivatives was reported. The new method was characterized with raw material easy to get, low manufacturing cost, mild reaction conditions and high yields. 2-Methylbenzoic acid and their derivatives were used as starting material, methyl 2-((bromotri-phenylphosphoranyl)methyl)benzoate and their derivatives were synthesized through esterification, free-radical bromination with N-bromobutanimide (NBS) and nucleophilic substitution with triphenylphosphine. After Wittig reaction and hydrolysis of carboxylic esters, 2-vinylbenzoic acid and their derivatives were obtained. Then through cyclization reaction with iodine (NBS), 3-iodo(bromo)methylisobenzofuran-1(3H)-one and their derivatives were obtained, which further react by elimination hydrogen halide with 1,8-diazabicyclo[5.4.0]under-7-ene to afford the target compounds. Eleven intermediates were new compounds.