63453-92-9

Upstream product

• 71-43-2 benzene 
• 106-51-4 p-benzoquinone 

Downstream Products

• 106-51-4 p-benzoquinone 
• 22479-78-3 4-(4-nitrophenoxy)phenol 

Relevant academic research and scientific papers

Oxidation of Benzene by the OH Radical. A Product and Pulse Radiolysis Study in Oxygenated Aqueous Solution

Hydroxyl radicals have been reacted with benzene.The major product is phenol.At low dose rate (γ-radiolysis) it is formed in 53percent yield with respect to the OH radical yield.This value increases to 93percent in alkaline solution (pH 12.3).With deuteriated benzene it is reduced to 39percent.In addition, more than fifteen different ring-opened and fragment products are formed.A good material balance (based on primary OH radical yield and oxygen consumption) was obtained. At high dose rate (pulse radiolysis) the major products are phenol, hydroquinone and cyclohexa-2,5-diene-1,4-diol.An important intermediate is the HO2./O2.- radical.Its rate of formation (kobsd = 800 s-1) has been followed by pulse radiolysis using tetranitromethane as a scavenger as well as conductimetrically (build-up of H+/O2.-). The results have been interpreted as follows: in their reaction with benzene, hydroxyl radicals yield the hydroxycyclohexadienyl radical 1.In the presence of oxygen, radical 1 undergoes reversible oxygen addition yielding four different hydroxycyclohexadienylperoxyl radicals: the cis- and trans-isomers of 6-hydroxycyclohexa-2,4-dienylperoxyl radical 3 and the cis- and trans-isomers of 4-hydroxycyclohexa-2,5-dienylperoxyl radical 4.As reported previously, in the equilibrium mixture of the radicals 1, 3 and 4 the concentrations of radical 3 represents only a few per cent of the total.It is suggested that 3 eliminates HO2. thereby yielding phenol.In basic solution deprotonation of 4 is followed by an O2.--elimination which opens up an additional route to phenol.The fact that phenol formation is not quantitative and its yield is reduced in the case of deuteriated benzene is due to another unimolecular decay route.The competing reaction is the intramolecular addition of the peroxyl radical function to a double bond (and subsequent fragmentation of the ring system).Since the HO2.-elimination is not very fast, bimolecular decay of the radicals 1, 3 and 4 (mainly of 4, 2k = 8.9 * 108 dm3 mol-1 s-1) plays an increasingly important role under the conditions of pulse radiolysis.As a consequence, the hydroquinone and cyclohexa-2,5-diene-1,4-diol yields increase with increasing dose rates under pulse radiolysis conditions (2 - 25 Gy pulse-1) as those of phenol and HO2. decrease.

Reaction of Aluminium Hydride-Triethylamine Complex with Selected Organic Compounds Containing Representative Functional Groups

The addition of triethylamine to a solution of aluminium hydride in tetrahydrofuran (THF), which was prepared by the addition of a calculated amount of hydrogen chloride in diethyl ether to solutions of sodium aluminium hydride in THF, provides very stable solutions of aluminium hydride-triethylamine complex (AHTEA).The reducing power of AHTEA complex in tetrahydrofuran toward 59 selected organic compounds containing representative functional groups under practical conditions (tetrahydrofuran, room temperature, the quantitative amount of reagent to compound) has been investigated.In this way, we have established that quantitative reduction of various organic functionalities can be readily achieved using the calculated quantity of AHTEA to avoid the use of excess reagent.This permits ready use of the aluminium hydride reagent in organic synthesis with high convenience and efficiency, with the possibility of an improved selectivity than that of aluminium hydride itself in tetrahydrofuran.

Radical Transport Reaction. Concurrent Transfer of Electron and Proton

Concurrent transport of electron and proton on the same molecule; formal hydrogen-transfer reaction, is succesfully realized in aprotic media by using 1-butyl-4,4'-bipyridinium cation radical (BuPPH*+), which is prepared from 1-butyl-4-(4-pyridyl)pyridinium ion.Hydrogen reduction with BuPPH*+ was discriminated from electron reduction with octylviologen cation radical by the chemoselective reduction preferring enedione to vic-dibromide in aprotic media.

MECHANISM OF ACID-CATALYSED REDUCTION OF AROMATIC ALDEHYDES AND p-BENZOQUINONE DERIVATIVES BY AN NADH MODEL COMPOUND

A series of aromatic aldehydes have successfully been reduced by N-metylacridan (AcH2) in the presence of perchloric acid (HClO4) in a mixture of acetonitrile and acetic acid (MeCN/MeCOOH, 4:1 v/v) at 323 K.The effects of HClO4 as well as Mg(ClO4)2 on hydride-transfer reactions from AcH2 to a series of p-benzoquinone derivatives (Q) in MeCN have also been examined.Perchloric acid shows both accelerating and retarding effects on the hydride-transfer reactions depending on the p-benzoquinone derivative.It is shown that AcH2 forms a 1 : 1 complex with HClO4 and the protonated species AcH3+ is inactive for the reduction of p-benzoquinon derivatives.Thus, for p-benzoquinone drivatives being weak oxidants such as p-benzoquinone which have the redox potentials E0(Q/Q-.) 0(Q/Q-.) > 0, HClO4 shows an overall retarding effect on the reduction where HClO4 has hardly catalysed the reaction of free AcH2 with Q.A proposed reaction mechanism involving electron transfer from AcH2 to Q followed by proton transfer from AcH2+ to Q-. in the rate-determining step of the hydride-transfer reactions provides a quantitative evaluation of the single and unified correlation of the logarithm of the rate constant for the hydride-transfer reactions from free AcH2 to Q with the redox potential of Q in the absence and presence of Mg(ClO4)2 or HClO4.The electronic substituent effects on the rate of acid-catalysed reduction of aromatic aldehydes by AcH2 are shown to be very small, as being compatible with those observed for liver alcohol dehydrogenase (LADH)-catalysed reduction of the corresponding aldehydes by NADH.Moreover, the absolute value of the rate constant for the hydride-transfer step from free AcH2 to the protonated benzaldehyde in our model system is also shown to be compatible with that in the LADH-enzyme system.

REDUCTION OF ALDEHYDES AND KETONES TO ALCOHOLS WITH HYDROUS ZIRCONIUM OXIDE AND 2-PROPANOL

Reduction of aldehydes and ketones with 2-propanol was found to proceed efficiently in the presence of hydrous zirconium oxide.The reaction is performed simply and the products are easily isolated in the pure state by filtering off the hydrous zirconium oxide, followed by evaporation of solvents.