75966-32-4

Upstream product

• 98-51-1 4-tert-butyltoluene 
• 18880-00-7 1-(bromomethyl)-4-(1,1-dimethylethyl)benzene 

Downstream Products

• 939-97-9 4-tert-Butylbenzaldehyde 
• 79135-57-2 1,2-Dibromo-1,2-bis(p-tert-butylphenyl)ethane 
• 98-73-7 4-(1,1-dimethylethyl)benzoic acid 
• 79135-54-9 (E)-1,1'-(1,2-ethenediyl)bis(4-butyl)benzene 
• 6325-63-9 (E)-3,3'-dimethoxystilbene 
• 117953-25-0 6-t-butyl-1,2,3-tris-(4-t-butylphenyl)azulene 
• 79135-56-1 1,2-Dichloro-1,2-bis(p-tert-butylphenyl)ethane 
• 79135-60-7 1-tert-butyl-(4-dichloromethyl)benzene 
• 79135-62-9 1,2-bis(4-(tert-butyl)phenyl)ethan-1-one 
• 61440-86-6 bis(4-tert-butylphenyl)acetylene 

Relevant academic research and scientific papers

Readily Reconfigurable Continuous-Stirred Tank Photochemical Reactor Platform

A new modular photochemical continuous stirred-tank reactor (CSTR) design is described, based upon the development of light-source units that can be fitted to the previously described fReactor CSTR platform. In addition to use in homogeneous photochemical reactions (e.g., photoredox-catalyzed hydroamination), these units are especially well suited to handling multiphasic mixtures, exemplified here in solid-liquid (Wohl-Ziegler bromination) and gas-liquid (photocatalytic oxidative decarboxylation) reactions. The use of slurries as input feeds allows for the intensification of photochemical brominations, while the modular nature of the system facilitates the simple integration of downstream reaction steps, exemplified here in a continuous synthesis of an intermediate for the antihypertensive drug valsartan.

E-Stilbene derivatives synthesized by stereoselective reductive coupling of benzylic gem-dibromide promoted by Cu/polyamine

Stereoselective reductive coupling reaction of benzylic gem-dibromide promoted by Cu/polyamine produces E-stilbene derivatives with high yield under mild conditions. It provides a short pathway to synthesize symmetrical and asymmetrical E-stilbene derivatives using cheap reagents and alkenyl-free starting material together with easy workup.

Easy access for the synthesis of 2-aryl 2,3-dihydroquinazolin-4(1H)-ones using gem-dibromomethylarenes as synthetic aldehyde equivalent

One step synthesis of 2,3-dihydroquinazolin-4(1H)-ones from gem-dibromomethylarenes using 2-aminobenzamide is described. Gem-dibromomethylarenes are used as aldehyde equivalent for the efficient synthesis of 2,3-dihydroquinazolin-4(1H)-ones, this synthesis takes shorter reaction time with quick isolation and excellent product yield. This journal is the Partner Organisations 2014.

A scalable procedure for light-induced benzylic brominations in continuous flow

A continuous-flow protocol for the bromination of benzylic compounds with N-bromosuccinimide (NBS) is presented. The radical reactions were activated with a readily available household compact fluorescent lamp (CFL) using a simple flow reactor design based on transparent fluorinated ethylene polymer (FEP) tubing. All of the reactions were carried out using acetonitrile as the solvent, thus avoiding hazardous chlorinated solvents such as CCl4. For each substrate, only 1.05 equiv of NBS was necessary to fully transform the benzylic starting material into the corresponding bromide. The general character of the procedure was demonstrated by brominating a diverse set of 19 substrates containing different functional groups. Good to excellent isolated yields were obtained in all cases. The novel flow protocol can be readily scaled to multigram quantities by operating the reactor for longer time periods (throughput 30 mmol h-1), which is not easily possible in batch photochemical reactors. The bromination protocol can also be performed with equal efficiency in a larger flow reactor utilizing a more powerful lamp. For the bromination of phenylacetone as a model, a productivity of 180 mmol h -1 for the desired bromide was achieved.

Electrochemical method for the preparation of dibromomethyl, bis(bromomethyl), and bis(dibromomethyl) arenes

Electrochemical bromination of alkyl aromatic compounds by two-phase electrolysis yields the corresponding α,α-dibrominated products. The reaction has been carried out in a single-compartment electrochemical cell using aqueous sodium bromide (40-50%), containing a catalytic amount of HBr as electrolyte, and chloroform, containing an alkyl aromatic compound, as the organic phase with a Pt plate as anode at 10-15C. Two-phase electrolysis results in high yields (70-90%) of dibromomethyl, bis(bromomethyl), and bis(dibromomethyl) arenes, depending upon the charge passed.

Environmentally benign electrophilic and radical bromination 'on water': H2O2-HBr system versus N-bromosuccinimide

A H2O2-HBr system and N-bromosuccinimide in an aqueous medium were used as a 'green' approach to electrophilic and radical bromination. Several activated and less activated aromatic molecules, phenylsubstituted ketones and styrene were efficiently brominated 'on water' using both systems at ambient temperature and without an added metal or acid catalyst, whereas various non-activated toluenes were functionalized at the benzyl position in the presence of visible light as a radical activator. A comparison of reactivity and selectivity of both brominating systems reveals the H2O2-HBr system to be more reactive than NBS for benzyl bromination and for the bromination of ketones, while for electrophilic aromatic substitution of methoxy-substituted tetralone it was higher for NBS. Also, higher yields of brominated aromatics were observed when using H2O2-HBr 'on water'. Bromination of styrene reveals that not just the structure of the brominating reagent but the reaction conditions: amount of water, organic solvent, stirring rate and interface structure, play a key role in defining the outcome of bromination (dibromination vs bromohydroxylation). In addition, mild reaction conditions, a straightforward isolation procedure, inexpensive reagents and a lower environment impact make aqueous brominating methods a possible alternative to other reported brominating protocols.

Visible-light-promoted Wohl-Ziegler functionalization of organic molecules with N-bromosuccinimide under solvent-free reaction conditions

The visible-light-induced transformation of toluenes with N-bromosuccinimide (NBS) under solvent-free reaction conditions (SFRC) was studied. The reaction took place in spite of the very restricted molecular motion; toluenes could be regioselectively converted to benzyl bromides. Selective radical-chain reactions with NBS were carried out in liquid/liquid and in solid/solid systems; furthermore, reactions could be performed in the presence of air. The radical scavenger TEMPO (=2,2,6,6-tetramethylpiperidin-1- yloxy) completely suppressed the side-chain bromination of toluenes with NBS under SFRC. Electron-withdrawing groups decreased the reactivity of the toluenes, and the Hammett reaction constant ρ+ = -1.7 indicated involvement of polar radical intermediates with electrophilic character.

Free radical bromination by the H2O2-HBr system on water

An aqueous solution of hydrogen peroxide and hydrogen bromide illuminated by a 40 W incandescent light bulb serves as a source of bromine radicals. Various substituted toluenes (H, Me, tBu, Br, COOEt, COPh, NO2) were brominated at the benzyl position. This haloperoxidase-like system for benzylic bromination does not require the presence of metal ions or an organic solvent for efficient conversion of methyl-arenes to benzyl bromides.

Visible light induced 'on water' benzylic bromination with N-bromosuccinimide

Benzylic bromination of various 4-substituted toluenes (Me, tert-Bu, COOEt and COMe) was effectively conducted with NBS in pure water and with a 40 W incandescent light-bulb as an initiator of the radical chain process, while electron donating groups (OMe and NHAc) directed the reaction to electrophilic aromatic substitution.

Association of fluorous "phase-vanishing" method with visible-light activation in benzylic bromination by bromine

In this study the "phase-vanishing" method for diffusion-controlled addition of a reagent (Br2) to a reaction phase via a fluorous membrane (C8F18) is combined with an additional mode of activation (visible-light) to achieve the benzyl bromination of various alkyl-substituted aromatic compounds in a concentrated solution. Benzyl bromination of p-tert-butyl-toluene proceeded in various solvents including hexane and methanol, while the reaction of the neat substrate showed a similar selectivity as in carbon tetrachloride. The effect of the substituent on the para position of toluene on the course of bromination revealed three processes: benzyl bromination with H, Me, tBu and CO2Et substituents, aromatic bromination with OMe and NHAc substituents and the reaction of the 4-acetyl derivative at the substituent to form an α-bromo ketone. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.