19689-52-2

Upstream product

• 60-09-3 aniline yellow 
• 2491-52-3 4-nitroazobenzene 
• 60-09-3 4-Aminoazobenzene 

Downstream Products

• 60-09-3 aniline yellow 

Relevant academic research and scientific papers

Transfer Hydrogenation of Azo Compounds with Ammonia Borane Using a Simple Acyclic Phosphite Precatalyst

Tris(quinolin-8-yl)phosphite, P(Oquin)3, promotes the dehydrogenation of H3N·BH3 (AB) and the transfer hydrogenation of azoarenes using ammonia borane (AB) as H2 source. The metal-free reduction of azoarenes proceeds under mild reaction conditions upon which several diphenylhydrazine derivatives are obtained in high yields. The reactivity of P(Oquin)3 toward AB was evaluated through NMR in situ tests. The rate of the reaction, activation parameters, deuterium kinetic isotope effect (DKIE) and linear-free energy relationship were investigated. Such mechanistic and kinetic studies suggest that P(Oquin)3 is a precatalyst and that AB is likely involved in more than one stage of the reaction pathway. Furthermore, the kinetic data indicate that the reaction proceeds through an ordered transition state, possibly associative.

The influence of acid and sodium hydroxide admixtures on the hydrogenation of 4-aminoazobenzene

The kinetics of liquid-phase hydrogenation of 4-aminoazobenzene was studied in aqueous and aqueous-alcoholic solvents of various compositions including solvents with acetic acid and sodium hydroxide admixtures. Experiments showed that the rate of azo group hydrogenation substantially changed under the action of solvents. The introduction of the acid sharply increased reaction rates, whereas, when sodium hydroxide was introduced, the process acquired a stage character and the observed hydrogenation rates decreased. Changes in the rate of the reaction were found to depend on solvation interactions in solutions evidenced by hypso- and bathochromic shifts of the absorption maxima of 4-aminoazobenzene in solvents of various compositions. The experimental data were used to calculate the activation energies of hydrogenation of 4-aminoazobenzene in the solvents under investigation. The possibility of controlling the rate and selectivity of liquid-phase hydrogenation of azo compounds by varying the composition of solvents was grounded.

Regiospecific acylations of aromatics and selective reductions of azobenzenes over hydrated zirconia

Hydrated zirconia has been found to be an efficient and reusable catalyst for the regiospecific acylations of arenes and selective reductions of azobenzenes to produce benzophenones and hydrazabenzenes respectively.

Convenient reduction of azobenzenes and azoxybenzenes to hydrazobenzenes by sodium dithionite using dioctylviologen as an electron transfer catalyst

Various ezobenzenes and azoxybenzenes were reduced almost quantitatively to the corresponding hydrazobenzenes as sodium dithionite under mild conditions without the formation of aniline derivatives, using dioctyl viologen as an electron-transfer catalyst in acetonitrile-water.