Halogen Exchange in Near-Critical Water

Abstract

Bromoaromatics are ubiquitous in chemistry, and their manufacture is often wasteful. Halogen exchange under hydrothermal conditions constitutes a viable alternative for their synthesis in some cases. The preparation of 1,2-dibromobenzene and 1-bromo-2-chlorobenzene from 1,2-dichlorobenzene, by treatment with hydrobromic acid in hydrothermal media at temperatures ranging from 240˚C to 320˚C was investigated as a viable alternative to de novo synthesis. The effects of temperature, exchange duration and the presence of Fe 3+ salts on product yields are discussed. Yields for both targeted haloarenes of up to 37% and 48%, respectively, were achieved, with very limited formation of 1,3-and 1,4-dihalobenzene isomers. A mechanism for halogen exchange was proposed.

Click chemistry-based synthesis of new 1,2,3-triazolo-benzoquinoline-3-carbonitriles: anticancer screening and DFT studies

“…Generally, the lower value of the energy gap indicates that the molecule is more reactive and less stable and vice versa. [40][41][42][43][44] According to the B3LYP/6-31G(d) method, HOMOs and LUMOs are shown in Fig. 4 and 5.…”