58784-38-6

Upstream product

• 35665-94-2 p-nitrophenyl p-nitrophenylacetate 
• 3282-33-5 1-(4-chlorophenyl)-2-diazoethanone 
• 4203-31-0 2-diazo-1-(4-nitrophenyl)ethanone 
• 108099-76-9 2,4-dinitrophenyl 4-nitrophenylacetate 

Downstream Products

• 33703-64-9 1-(p-nitrophenyl)-2-hydroxycyclobutene-3,4-dione 
• 50507-86-3 Diethylamide of p-nitrophenylacetic acid 
• 1497283-55-2 C₁₂H₁₆N₂O₃ 
• 104-03-0 4-nitrobenzeneacetic acid 
• 105625-84-1 3-[(E)-3-(4-Nitro-phenyl)-acryloyl]-5-[1-(4-nitro-phenyl)-meth-(E)-ylidene]-2-phenyl-3,5-dihydro-imidazol-4-one 
• 105625-86-3 5-[1-(4-Hydroxy-phenyl)-meth-(E)-ylidene]-3-[(E)-3-(4-nitro-phenyl)-acryloyl]-2-phenyl-3,5-dihydro-imidazol-4-one 
• 105625-82-9 3-[(E)-3-(4-Nitro-phenyl)-acryloyl]-2-phenyl-5-[1-phenyl-meth-(E)-ylidene]-3,5-dihydro-imidazol-4-one 

Relevant academic research and scientific papers

Ketene-forming eliminations from aryl phenylacetates promoted by R2NH/R2NH2+ in aqueous MeCN. Mechanistic borderline between E2 and E1cb

Elimination reactions of 2-X-4-NO2C6H3CH2C(O) OC6H3-2-Y-4-NO2 [X = H (1), NO2 (2)] promoted by R2NH/R2NH2+ in 70 mol % MeCN(aq) have been studied kinetically. The base-promoted eliminations from 1 proceeded by the E2 mechanism when Y = Cl, CF3, and NO2. The mechanism changed to the competing E2 and E1cb mechanisms by the poorer leaving groups (Y = H, OMe) and to the E1cb extreme by the strongly electron-withdrawing β-aryl group (2, X = NO2). The values of β = 0.14 and |β1g| = 0.10-0.21 calculated for elimination from 1 (Y = NO2) indicate a reactant-like transition state with small extents of proton transfer and Cα-OAr bond cleavage. The extent of proton transfer increased with a poorer leaving group, and the degree of leaving group bond cleavage increased with a weaker base. Also, the changes in the k1 and k-1/k2 values with the reactant structure variation are consistent with the E1cb mechanism. From these results, a plausible pathway of the change of the mechanism from E2 to the E1cb extreme is proposed.

Amination of phenylketene revisit. Substituent effect on reactivity

The asymmetric stretching frequencies of the ketene group of the m,p-substituted phenylketenes were found to be correlated with σ The substituent effects for the second-order rate constants of phenylketenes with various amines were not correlated linearly

Aminoxyl radical addition to arylketenes

Kinetic studies of the addition of the aminoxyl radical TEMPO (2,2,6,6-tetramethylpiperidinylaminoxyl, TO) to the 4-substituted phenylketenes 8 (4-RC6H4CH=C=O, R=NO2, CN, Cl, H, CH 3, CH3O) and to 3-p

Spectroscopy and absolute reactivity of ketenes in acetonitrile studied by laser flash photolysis with time-resolved infrared detection

Laser flash photolysis with time-resolved infrared detection of transients (LFP-TRIR) has been used to study the IR spectroscopy and reactivity of a number of substituted ketenes, prepared by the 308-nm photolysis of α-diazocarbonyl precursors in acetonitrile solution at room temperature. The correlation of the experimental ketene asymmetric stretching frequency to the Swain-Lupton field (F) and resonance (R) effect substituent parameters was unsatisfactory, whereas the correlation to the inductive substituent parameter (σ1) of Charton gave excellent results. This suggests that the asymmetric stretching frequency of substituted ketenes depends mainly on the inductive (i.e., field) effect of the substituents. The mechanism and kinetics of the reactions of these ketenes with various amines in acetonitrile were also studied. An intermediate species identified as either zwitterionic ylide or amide enol formed in the nucleophilic addition of the secondary amine to the C(α) of the ketene is observed by TRIR. The decay of this species is assisted by the amine and is concomitant with the formation of an amide, the final product of the reaction. Our kinetic data on ketene amine reactions show a general trend, indicating a much higher reactivity (ca. 3 orders of magnitude difference in the corresponding rate constants) of secondary amines compared with that of tertiary amines. Secondary diethylamine shows reactivity similar to those observed for primary amines, while secondary piperidine seems to be, in general, somewhat more reactive. The observed trend is rationalized in terms of the steric effects exerted by both amine and ketene substituents. Our data on para-substituted phenyl ketenes provide support for the negative charge development on the ketene moiety in the transition state, with electron-withdrawing substituents accelerating and electron-releasing substituents slowing down the addition reaction.

Reactions of aryl phenylacetates with secondary amines in MeCN. Structure-reactivity relationship in the ketene-forming eliminations and concurrent E2 and E1cb mechanisms

Elimination reactions of aryl esters of arylacetic acids 1 and 2 promoted by R2NH in MeCN have been investigated kinetically. The reactions are second-order and exhibit β = 0.44-0.84, β(lg) = 0.41-0.50, and ρ(H) = 2.0-3.6. Bronsted β and β(lg) decrease with the electron-withdrawing ability of the β-aryl substituent. Hammett ρ(H) values remain nearly the same, but the β(lg) value increases as the base strength becomes weaker. Both ρ(H) and β decrease with the change of the leaving group from 4-nitrophenoxide to 2,4-dinitrophenoxide. The results are consistent with an E2 mechanism and a reaction coordinate with a large horizontal component corresponding to proton transfer. When the base-solvent system is changed from R2NH-MeCN to R2NH/R2NH2+-70 mol% MeCN(aq), the Bronsted β, ρ(H), and β(lg) decrease. Finally, the ketene-forming elimination reactions from p-nitrophenyl p-nitrophenylacetate promoted by R2NH/R2NH2+ buffers in 70 mol% MeCN(aq) have been shown to proceed by concurrent E2 and E1cb mechanisms.