79-94-7Relevant articles and documents
Instantaneous, facile and selective synthesis of tetrabromobisphenol a using potassium tribromide: An efficient and renewable brominating agent
Kumar, Lalit,Sharma, Vivek,Mahajan, Tanu,Agarwal
, p. 174 - 179 (2010)
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.
Electrophilic bromination in flow: A safe and sustainable alternative to the use of molecular bromine in batch
Van Kerrebroeck, Reinout,Naert, Pieter,Heugebaert, Thomas S.A.,D’hooghe, Matthias,Stevens, Christian V.
, (2019/06/10)
Bromination reactions are crucial in today’s chemical industry since the versatility of the formed organobromides makes them suitable building blocks for numerous syntheses. However, the use of the toxic and highly reactive molecular bromine (Br2) makes these brominations very challenging and hazardous. We describe here a safe and straightforward protocol for bromination in continuous flow. The hazardous Br2 or KOBr is generated in situ by reacting an oxidant (NaOCl) with HBr or KBr, respectively, which is directly coupled to the bromination reaction and a quench of residual bromine. This protocol was demonstrated by polybrominating both alkenes and aromatic substrates in a wide variety of solvents, with yields ranging from 78% to 99%. The protocol can easily be adapted for the bromination of other substrates in an academic and industrial environment.
Electrochemical synthesis of quinones and other derivatives in biphasic medium
Shanmugam,Kulangiappar,Ramaprakash,Vasudevan,Senthil Kumar,Velayutham,Raju
, p. 2294 - 2297 (2017/05/19)
Electrochemical synthesis of quinones has been attempted from phenols, 1,4-dihydroxybenzenes, 1,4-dihydroxynaphthalenes and related compounds using biphasic media. Excellent yields of quinones (98%) or brominated diols have been achieved with good current efficiency. Reuse of the electrolyte without any modification and quantitative conversion of substrate with theoretical amount of current are the advantages of this method.
Hexamethonium bis(tribromide) (HMBTB) a recyclable and high bromine containing reagent
Paul, Bappi,Bhuyan, Bishal,Purkayastha, Debraj D.,Dhar, Siddhartha S.,Patel, Bhisma K.
, p. 5646 - 5650 (2015/09/21)
A recyclable and high bromine containing di-(tribromide) reagent, hexamethonium bis(tribromide) (HMBTB) has been synthesized and utilized for the bromination of various organic substrates. The spent reagent hexamethonium bromide (HMB) can be effectively recycled by regenerating and reusing it without significant loss of activity. The crystalline and stable bis(tribromide) is an effective storehouse of very high percentage of active bromine requiring just half an equivalent of it for complete bromination. Both the Br3- moieties in HMBTB are nearly linear with Br-Br-Br angle of 179.55°.
Supramolecular organic frameworks of brominated bisphenol derivatives with organoamines
Lue, Jian,Han, Li-Wei,Lin, Jing-Xiang,Cao, Rong
experimental part, p. 3551 - 3557 (2012/03/27)
Reactions of two brominated bisphenol derivatives, tetrabromobisphenol-F (TBBPF) and tetrabromobisphenol-A (TBBPA), with various organoamines resulted in six supramolecular organic frameworks (SOFs), formulated as (TBBPF 2-)2·(HPZ+)2· (H 2PZ2+) (1), (TBBPF-)2· (H2PZ2+)·2H2O·2MeOH (2), (TBBPF) · (TBBPF-)· (HDABCO+)·H2O (3), (TBBPF) · (HMTA) (4), (TBBPA) · (HMTA) (5), and (TBBPA) 3· (HMTA)3·H2O (6) (PZ = piperazine; DABCO = diazabicyclo[2.2.2]octane; HMTA = hexamethylenetetramine). Compounds 1-6 were characterized by single-crystal and powder X-ray diffractions. The predominant driving forces in 1-6 are hydrogen bonds (H-bonds), by which the compounds assemble into supramolecular organic frameworks with versatile topological structures. Compound 1 contains TBBPF/PZ in a 2:3 ratio and exhibits 2D (two-dimensional) H-bonded supramolecular 4 4-sql layer structure built by the four-connected {H 2PZ2+} moieties and {TBBPF2-}. Compound 2 shows a 2-fold interpenetrated 3D (three-dimensional) H-bonded networks comprised by TBBPF/PZ in 2:1 ratio with the presence of solvent H2O and MeOH molecules, in which two identical pcu topological nets are recognized by choosing a decamer synthons as nodes. Compound 3 displays H-bonded 4 4-sql layer structure built by 2:1 TBBPF and DABCO, as well as one H2O per formula unit. Compounds 4 and 5 assemble into 1D (one-dimensional) H-bonded zigzag chains via the alternate linkage of HMTA with TBBPF/TBBPA in a similar fashion. Compound 6 generates an interesting hexamer subunit (HMTA ...TBBPA ...HMTA ...TBBPA ...HMTA...TBBPA), which can be viewed as a fragment of three repeating units for a zigzag chain observed in compound 5. A pair of the hexamer subunits is further connected by two water molecules to form an H-bonded molecular oligomer. Importantly, halogen bonds (X-bonds) have been observed in compounds 4-6 that exhibit 1D and 0D H-bonded supramolecular structures.
Process for the Preparation of Tetrabromobisphenol A
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Page/Page column 5-6, (2010/02/17)
A process for preparing tetrabromobisphenol A, which comprises: i) reacting bisphenol A and bromine in dichloromethane in the presence of aqueous hydrogen peroxide at a temperature in the range of room temperature to the reflux temperature, wherein said dichloromethane is present in an amount sufficient for substantially dissolving brominated derivatives of said bisphenol A formed thereby, ii) separating the substantially solid-free reaction mixture obtained in step i) into aqueous and organic phases, precipitating tetrabromobisphenol A from the organic phase and isolating said precipitated tetrabromobisphenol A from said organic phase.
A PROCESS FOR THE PREPARATION OF TETRABROMOBISPHENOL A
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Page/Page column 20-27, (2008/06/13)
A process for preparing tetrabromobisphenol A, which comprises: i) reacting bisphenol A and bromine in dichloromethane in the presence of aqueous hydrogen peroxide at a temperature in the range of room temperature to the reflux temperature, wherein said dichloromethane is present in an amount sufficient for substantially dissolving brominated derivatives of said bisphenol A formed thereby, ii) separating the substantially solid-free reaction mixture obtained in step i) into aqueous and organic phases, precipitating tetrabromobisphenol A from the organic phase and isolating said precipitated tetrabromobisphenol A from said organic phase.
1-Benzyl-4-aza-1-azoniabicyclo[2.2.2]octane tribromide as a regenerable and useful reagent for bromination of phenols under mild conditions
Hajipour, Abdol R.,Pourmousavi, Seied A.,Ruoho, Arnold E.
, p. 796 - 800 (2007/10/03)
1-Benzyl-4-aza-1-azoniabicyclo[2.2.2]octane tribromide has been examined over several phenolic compounds under mild conditions. The reaction gives brominated phenols in good to excellent yields. Straightforward work-up of the reaction yields pure products in several cases.
Eco-friendly method of preparation of high purity tetrabromobisphenol-A
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Example 1, (2008/06/13)
A highly pure and colorless tetrabromobisphenol-A (TBBPA) possessing melting point in the range of 178-182° C. is prepared in yields of 50-70% in first batch and 90-100% when the spent organic layer is recycled. In this method, the corrosive liquid bromine is displaced by sodium bromide/hydrobromic acid as brominating agent. Further, sodium bromate is used as an oxidizing as well as brominating agent to utilize the hydrobromic acid that is produced during the bromination of bisphenol-A (BPA). The reaction is conducted at 10-15° C. in a mixture of methylene chloride-water or carbon tetrachloride-water in the presence of hydrochloric acid and sodium lauryl sulfate. The crystalline product settled at the bottom of the reaction vessel is filtered, washed, dried and weighed. The spent organic layer is recycled in subsequent batches to maximize the overall yield of product recovered directly as solid and to minimize generation of organic effluent.
A controlled and selective bromination of phenols by benzyltriphenylphosphonium tribromide
Hajipour, Abdol Reza,Mallakpour, Shadpour E.,Imanieh, Hossein,Pourmousavi, Seied A.
, p. 272 - 275 (2007/10/03)
Reactions of phenols with benzyltriphenylphosphonium tribromide in dichloromethane-methanol mixture (2:1) gave mono, di and tri brominated phenols at room temperature with high selectivity and good yields.
