497-16-5

Upstream product

• 931-88-4 1,2-cyclooctene 
• 91-20-3 naphthalene 
• 67-66-3 chloroform 
• 10028-15-6 ozone 
• 538-58-9 1,5-diphenyl-1,4-pentadiene-3-one 
• 108-97-4 4-pyrone 
• 10034-85-2 hydrogen iodide 
• 71-43-2 benzene 
• 636-38-4 3-hydroxy-2-oxo-propionaldehyde 
• 106-51-4 p-benzoquinone 

Downstream Products

• 19218-70-3 mesoxalaldehyde tris-phenylhydrazone 

Relevant academic research and scientific papers

IN-SITU DECOMPOSITION OF PEROXIDES DURING THE OZONOLYSIS OF ALKENES

The invention relates to a method for carrying out the in-situ decomposition of peroxides during the ozonolysis of optionally substituted alkenes in order to form the corresponding aldehydes or ketones. According to the method, the optionally substituted alkenes are reacted in water, a C1-C4 carboxylic ester, a C1-C4 carboxylic acid, a water/C1-C4 carboxylic acid mixture, a C1-C6 alcohol or in a water/C1-C6 alcohol mixture at a temperature ranging from -30 °C to +50 °C, in the presence of a heterogeneous inorganic catalyst selected from the group consisting of iridium, manganese, cobalt, silver, gold, palladium, platinum or ruthenium, which is applied to a supporting material selected from the group consisting of calcium carbonate, coal, titanium dioxide, magnesium oxide, zirconium oxide, silica or aluminum oxide or in the presence of a homogeneous inorganic catalyst selected from the group consisting of transition metal catalysts while simultaneously decomposing peroxides with ozone. Afterwards, the catalyst is separated out from the reaction mixture once the ozonolysis is complete thus obtaining corresponding aldehydes and ketones.

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.