In my master’s thesis, I synthesized a number of activated ketones and alcohols and investigated their transformations using N-halogenating reagents in the alternative solvent 1,1,1,3,3,3-hexafluoroisopropanol (HFIP). In reactions where an excess of N-bromosuccinimide (NBS) was used, rapid bromination occurred at the activated site of the aromatic compound, followed by a slower ipso substitution. During the ipso substitution step, the functional group was cleaved from the activated aromatic ring and replaced by a bromine atom, yielding a dibrominated aromatic product. I examined the influence of the aromatic compound structures (activation and substitution of the aromatic ring, effect of alkyl chain length and hindrance) as well as the effect of varying amounts of NBS on the transformation. Additionally, I isolated potential side products, which provided further insight into the reaction pathway. To gain a deeper understanding of the transformations, I monitored one of the reactions using ¹H NMR spectroscopy. The analysis of results confirmed the proposed reaction pathway.
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