Reaction of bromine with 4,5-dimethyl-1,4-cyclohexadiene-1,2-dicarboxylic acid: a green chemistry puzzle for organic chemistry students

Green Chemistry Letters and Reviews

Chitra Chandrasekhar¹ 

关键词: undergraduate organic chemistry laboratory;    aromatization;    bromination;    gas chromatography–mass spectrometry;   

DOI  :  10.1080/17518250903410090

学科分类：化学（综合）

来源: Taylor & Francis

【 摘 要 】

Bromination of an alkene is a typical addition reaction covered in an introductory organic chemistry course and laboratory. In this undergraduate organic chemistry laboratory exercise, students studied the bromination of a 4,5-dimethyl-1,4-cyclohexadiene-1,2-dicarboxylic acid. The reaction has an unexpected outcome as bromination yields the aromatic product, 4,5-dimethylphthalic acid. Green chemistry modification involves application of a “bromide/peroxide reaction” with NaBr/H2O2 in an acidic medium as an in situ source of bromine. The experiment was carried out as a two-day exercise and the students integrated molecular modeling, interpretation of mass spectra, knowledge of stability of organic compounds, and knowledge of the reaction mechanisms of addition and elimination to explain the experimental outcome.

【 授权许可】

Unknown