A Unique Approach to the Synthesis of 2,3,4,5-Substituted Polybrominated Biphenyls: Quantitation in FireMaster FF-1 and FireMaster BP-6

Abstract

A scheme is presented that allows the efficient synthesis of four anilines (3,5-di-, 3,4,5-tri-, 2,3,4,5-tetra-, and 2,3,4,5,6-pentabromoanilines) as well as 1,2,3,4-tetrabromobenzene from a single starting material. All of these products are useful precursors in the synthesis of polybrominated biphenyls (PBBs), The aryl-aryl coupling of bromoanilines with 1,2,3,4-tetrabromobenzene provides a versatile approach to the synthesis of 2,3,4,5-tetrasubstituted PBBs for the first time. The synthesis and characterization of nine such PBBs are reported here. Interestingly, aside from the desired coupling product, the 2,2ʹ,3,3ʹ,4,4ʹ,5,5ʹ-octabromobiphenyl was a byproduct of each coupling reaction, ranging from less than 2% to 63% of the polybrominated biphenyl products. Capillary gas chromatographic quantitation of the nine synthetic PBBs in fireMaster FF-1 and fireMaster BP-6 is presented. © 1989, American Chemical Society. All rights reserved.