18939-92-9

Upstream product

• 13389-70-3 bis(4-methylphenyl)methyl chloride 
• 124-41-4 sodium methylate 
• 285129-99-9 di-p-tolylmethyl acetate 
• 67-56-1 methanol 
• 55816-25-6 bis(4-methylphenyl)methanone hydrazone 
• 1141-08-8 4,4'-dimethylthiobenzophenone 
• 885-77-8 4,4'-dimethylbenzhydrol 
• 32076-77-0 4,4'-dimethyldiphenylcarbene 

Downstream Products

• 67-56-1 methanol 
• 285129-99-9 di-p-tolylmethyl acetate 

Relevant academic research and scientific papers

Solvolytic reactivity of pyridinium ions

The leaving group abilities of pyridine, 4-methylpyridine, and 4-chloropyridine in SN1 solvolytic reactions have been determined by analyzing the rate constants of X,Y-substituted benzhydrylpyridinium salts obtained in various solvents. By applying the linear free energy relationship equation, log k = sf (Ef + Nf), the nucleofuge specific parameters of 4-substituted pyridine have been extracted. Because of solvation in the reactant ground state, the reactivity (nucleofugality, Nf) of a given pyridine decreases as the polarity of the solvent increases. High slope parameters (sf > 1) may be due to the spread of the energy levels of the benzhydrylium ion/pyridine pair intermediates in comparison to benzhydrylium ion/chloride pairs (sf ≈ 1). Because of slow heterolysis step of pyridinium salts in various solvents, some are stable under normal conditions.

Photolysis of Tetraarylmethanes and 3-(Triarylmethyl)pyridines

Upon UV irradiation in benzene-methanol (1:2) tetraarylmethanes or 3-(triarylmethyl)pyridines underwent an α,α-elimination of two aryl groups to give biaryls or 3-arylpyridine, and two corresponding carbene intermediates.The latters afforded methyl ethers by O-H insertion to methanol.

Radical ions in photochemistry. Carbon-carbon bond cleavage of radical cations in solution: Theory and application

The cleavage of radical cations of two series of alkanes, 1,1,2-triaryl- and 1,1,2,2-tetraarylalkanes, generated by photoinduced single electron transfer in acetonitrile-methanol, occurs with formation of radical and carbocation fragments. The radical cations of some unsymmetrically substituted alkanes cleave to give all four of the possible products, two hydrocarbons emanating from the radicals and two methyl ethers from the carbocations, in proportion to the oxidation potentials of the two possible radical fragments. There is an excellent linear correlation between the logarithm of the observed ratio of products and that calculated from the reported electrochemically determined oxidation potentials (r = 0.998, 5 points). The proportionality constant (1.27) for this relationship is close to unity which indicates that the product ratio is determined by the relative rates of cleavage in the two possible modes or by equilibration of the radicals and carbocations before separation of the geminate radical carbocation pair and not by equilibration upon reencounter of freely solvated radical and carbocation fragments. The effect of temperature on the relative oxidation potentials of the radicals studied is small and can be neglected when radicals of the same order (i.e., both secondary or both tertiary) and of similar size are compared. The ratio of products obtained upon cleavage of the radical cation at 25 °C can be used to determined standard oxidation potentials of radicals. The oxidation potential of the diphenylmethyl radical (0.350 V vs SCE) has been accepted as the primary standard and the (4-methyl-phenyl)phenylmethyl (0.265 V) and bis(4-methylphenyl)methyl (0.188 V) radicals are established as secondary standards against which the oxidation potentials of other radicals can be measured. Oxidation potentials of several 4-substituted cumyl radicals have been determined by this photochemical method. There is a good (r = 0.987, 5 points) linear correlation between the measured oxidation potentials and the σ+ substituent constants. The reaction constant is appropriately negative and large (p = -6).

The Absolute Kinetics of Several Reactions of Substituted Diphenylcarbenes

4,4'-dibromo-, 4-bromo-, 4,4'-dichloro-, 4-chloro-, 4-methyl-, 4,4'-dimethyl-, 4-phenyl-, 4-carbomethoxyl-, 4-cyano-, 4-cyano-4'-methyl-, and 4,4'-dimethyldiphenyldiazomethane were studied by laser flash photolysis.Excitation of the diazo compounds at 308 nm produced the corresponding diarylcarbenes.The kinetics of the reaction of the substituted carbenes with alkanes and methanol were examined.Hydrogen abstraction rates are largely insensitive to ring substitution, while the methanol reaction is accelerated considerably by p-methyl substitution and retarded by a para electron-withdrawing substituent.

Electrochemical Oxidation of Benzophenone Hydrazones

The anodic oxidation of benzophenone hydrazones (1) was found to give several products, depending upon the electrolysis conditions employed such as electrode material, temperature, and electrolyte composition.For example, the oxidation using a platinum anode at room temperature in LiClO4-MeCN afforded exclusively benzophenone azines (2), whereas in NaOMe-MeOH benzophenone dimethyl acetals (3) were formed as the main products.On the other hand, the oxidation using a graphite anode in refluxing MeOH containing NaOMe gave diphenylmethyl methyl ethers (4), along with diphenylmethanes (5).When the analogous electrolysis was conducted in the presence of methacrylic acid derivatives, corresponding diphenylcyclopropanes (7) were obtained in relatively high yields.

Hydrozirconation of Thioketones. A Simple, Convenient Entry into a Variety of Organosulfur Compounds. An Intersting Ether Synthesis

Aromatic and aliphatic thioketones undergo hydrozirconation at room temperature with (C5H5)2Zr(H)Cl to give sulfur-zirconium compounds, R2CHSZr(Cl)(C5H5)2.Cleavage of the latter by bromine or N-bromosuccinimide affords sulfenyl bromides, acid chlorides give thioesters, methyloxalyl chloride gives a thiooxalate, methyl vinyl ketone results in the formation of the β-keto sulfide, and carbonylation followed by bromination in alcohol affords the ether.Yery mild conditions are utilized for all of these reactions.Mechanisms are proposed for the interesting ether synthesis.