10.1039/c39920000183
The research focuses on the stepwise synthesis of unsymmetrically substituted 1,19-dibromo-a,c-biladienes and their conversion into biliverdins, corroles, and azaporphyrins. The purpose of this study was to develop an efficient route for the synthesis of biliverdins, which are open-chain tetrapyrroles with significant biological importance, and to adapt this methodology for the preparation of symmetrical biliverdins as well as corroles and azaporphyrins. The researchers successfully synthesized 1,19-dibromo-a,c-biladienes via the tripyrrene route and converted them into biliverdins, corroles, and azaporphyrins under appropriate reaction conditions. Key chemicals used in the process included 2-bromo-5-formylpyrrole, dipyrromethanedicarboxylic acid, toluene-p-sulfonic acid, dry HBr gas, and dimethyl sulfoxide (DMSO), among others. The study concluded that the DMSO procedure was unique for efficient biliverdin formation, and further mechanistic studies were ongoing. The research was supported by grants from the National Institutes of Health and Roswell Park Cancer Institute.