69373-33-7

Upstream product

• 110-22-5 diacetyl peroxide 
• 103-79-7 1-phenyl-acetone 
• 18649-43-9 4-methoxyphenyllead(IV) triacetate 
• 57918-71-5 1-Phenyl-2-propanone Potassium Enolate 

Downstream Products

• 96585-35-2 N-phenyl-2,5-dimethyl-3,4-diphenylpyrrole 
• 7584-72-7 meso-2,3-diphenylsuccinic acid 
• 79823-43-1 1-benzyl-3,4,-diphenyl-2,5-dimethylpyrrole 

Relevant academic research and scientific papers

α-Arylation of ketones by aryllead triacetates. Effect of methyl and phenyl substitution at the α position

An examination of the α-arylation of a number of ketones and their enolate salts by p-methoxyphenyllead triacetate provides further evidence for a very marked selectivity in the arylation reaction. It is found that the reaction proceeds well at tertiary α-carbons and at secondary centres activated by the presence of a phenyl group, but fails where the secondary centre is unactivated and at primary α-carbons.

Copper-Mediated Oxygenation of Aldehydes and Internal Cannizzaro-like Rearrangement of Phenylglyoxal

Under the influence of Cu(II) in MeOH containing py and Et3N, PhCH2CHO undergoes competitive O2-dependent conversions to PhCHO and phenylglyoxal.The latter, as the MeOH hemiacetal, undergoes a Cu(II)-catalyzed rearrangement to PhCHOHCOOMe and a Cu(II) oxidation to PhCOCOOMe, and there appears to be independent O2-mediated production of PhCOCOOH.Phenylglyoxal also undergoes oxidative cleavage to PhCOOH, but does not give rise to PhCHO.The homologous aldehyde PhCH2CH2CHO is converted mainly via PhCH2CHO to a product mixture derived from the latter.This result is interp reted in terms of preferential C-C cleavage of an α-hydroxyperoxide intermediate initially formed from PhCH2CH2CHO.The alternative pathway for this intermediate, dehydration to α-keto aldehyde PhCH2COCHO, is barely competitive, because the independently prepared α-keto aldehyde gives a distinct set of products under the reaction conditions.The preference for cleavage over dehydration explains the previously published finding of a stepwise degradation of long-chain aldehydes to formate units by the Cu(II)-py-Et3N-MeOH-O2 system.Product comparisons using either an O2 atmosphere or a N2 atmosphere (with varying equivalents of CuII) permit a distinction between stoichiometric Cu(II) oxidations and O2-dependent reactions.Mechanism are proposed for the observed transformations.

Stereoisomer Effects on the Paal-Knorr Synthesis of Pyrroles

The neurotoxicity of n-hexane has been postulated to result from the reactivity of its γ-diketone metabolite, 2,5-hexanedione (1), with lysil amino groups of proteins to form pyrroles (Paal-Knorr synthesis).We have synthesized a series of 3,4-disubstituted γ-diketones in order to explore the relationship between rate of pyrrole formation and neurotoxicity.The γ-diketones were prepared through oxidative coupling of ketones.Yields were improved to 60-70percent with the use a Soxhlet apparatus containing PbO2 in the extraction thimble.Diketones prepared were 3,4-dimethylhexane-2,5-dione (2), 3,4-diethylhexane-2,5-dione (3), 3,4-diisopropylhexane-2,5-dione (4), and 3,4-diphenylhexane-2,5-dione (5).The reactions yielded mixtures of the d,l (a) and meso (b) diastereomers, which were separated by column chromatography, fractional distillation, or crystallization.Structures of the diastereomeric forms were established by 13C NMR techniques and, in the case of 4b, by single crystal X-ray diffraction.The relative reactivities of the d,l and meso isomers of each γ-diketone were determined with benzylamine in cyclohexane and the rate of pyrrole formation was determined by HPLC.For each pair of diastereomeric diketones the d,l reacted 4-40 times faster than the meso form.The reactivities of the γ-diketones were in the order 2 > 1 > 3 > 5 > 4 with pseudo-first-order rate constants ranging from 4*10-4 to 3*10-8 s-1 at 30 deg C.