Instantaneous, Facile and Selective Synthesis of Tetrabromobisphenol A using Potassium Tribromide: An Efficient and Renewable Brominating Agent

Abstract

An instantaneous method for the bromination of bisphenol A has been reported using potassium tribromide for the first time as an efficient brominating agent affording the corresponding tetrabromobisphenol A in a reaction time of only 5−10 min at ambient temperature in high yields (99%) and purity (>99%), free from reaction byproduct and having very low ionic impurities. Mild reaction conditions and simple workup provide a practical and commercially viable route for the synthesis of the largest selling flame retardant. The generated HBr during the bromination reaction is used either in the preparation of value-added brominated products or is disposed of as waste, causing serious environmental problems. An environmentally acceptable method for an inbuilt recycling of HBr by its neutralisation, thereby generating additional amounts of metal bromide and recovering the solvent from the liquid mixture has been designed and developed. The KBr used for the preparation of potassium tribromide can be recovered, regenerated in additional amounts, and reused without any significant loss.

Synthesis and Biological Properties of 2(5H)-Furanones Featuring Bromine Atoms on the Heterocyclic Ring and/or Brominated Substituents

“…Notably, compounds 411 and 412 were proved capable to release in aqueous media nitric oxide [230], a compound which has been shown to influence biofilm dispersal in P. aeruginosa [231] and to control biofilm properties at picomolar to nanomolar concentrations [232]. It was also observed that the most potent and nonbactericidal compound in the biofilm inhibition assay was fimbrolide-NO donor hybrid compound 411b, which showed a 73% decrease in biofilm biomass [230]…”

“…Furthermore, in 2015, cadiolides C (359c) and A (359a) were synthesized by Franck and coworkers [213] by using the one-pot reaction of a-hydroxyketones, dioxinones and aryl aldehydes, which they had previously employed in the synthesis of cadiolide B (359b) [223]. As shown in Scheme 132, cadiolide C (359c) was obtained in 47% yield by reacting 1.0 equiv of a-hydroxyketone 359, 2.0 equiv of dioxinone 408 and 1.0 equiv of aldehyde 228 with 2.0 equiv of Et 3 N in toluene under microwave irradiation at 150 °C for 5 min and treatment of the resulting reaction mixture with 1 M HCl followed by BBr 3 -mediated Odemethylation of the resulting product [230].…”

“…Notably, cadiolide C appeared capable to inhibit the bacterial growth of Bacillus cereus (CECT 148), Salmonella typhi (CECT 409) and E. coli 405 with a MIC value of 3.90 µg/mL and cadiolide A required the same concentration of tetracycline to inhibit the bacterial growth of S. typhi and E. coli 405 with a MIC value of 8.81 µg/mL [213]. Compounds of general formula 411, including 411a and 411b, were synthesized in high yields from the corresponding fimbrolide analogues 413 (Scheme 134) [230], which in turn were prepared by sulfuric acidmediated cyclization of brominated 2-alkyllevulinic acids [103]. Allylic bromination of compounds 413 using NBS as the brominating reagent in the presence of benzoyl5peroxide gave compounds 413 in good to excellent yields, which were then converted to the corresponding nitrooxy-substituted fimbrolides 411 in 71-80% yield by treatment with 1.2-1.7 equiv of AgNO 3 in acetonitrile at 70 °C.…”

“…One-pot multicomponent synthesis of cadiolide A (359a) Finally, in concluding this section, it is worth mentioning that, in 2013, Kutty, Kumar and coworkers designed, synthesized and evaluated some fimbrolide-nitric oxide donor hybrids as antimictrobial agents and found that 3-(1nitroxybutyl)-5-(dibromomethylene)-2(5H)-furanone (411a), 3-(1-nitroxydodecyl)-5-(dibromomethylene)-2(5H)-furanone (411b) and 1-[5-(dibromomethylene)-2oxo-2,5-dihydrofuran-3-yl]butyl 2-(nitrooxy)acetate (412)(Figure 28) were particularly effective as antimicrobial compared to the nonhybrid naturally-occurring fimbrolides as revealed by Pseudomonas aeruginosa QS reporte assays and biofilm inbition assays[230].…”

Development of a Monoclonal Antibody-Based Enzyme-Linked Immunosorbent Assay for Tetrabromobisphenol A

“…Synthesis of 6,6-bis(3,5-dibromo-4-hydroxyphenyl)heptanoic acid (hapten). (24,26) 6,6-Bis(4-hydroxyphenyl)heptanoic acid (A [ Fig. 1], 3.14 g, 10 mmol) was dissolved in 40 mL acetic acid, then a solution of bromine (25.73 g, 0.16 mol) in 20 mL acetic acid was added dropwise.…”