6465-00-5

Upstream product

• 6465-01-6 (4-nitrophenyl)carbamic acid phenyl ester 
• 100-28-7 4-Nitrophenyl isocyanate 
• 108-95-2 phenol 
• 1170292-50-8 phenyl (2,4,6-trinitrophenyl) carbonate 
• 106-50-3 1,4-phenylenediamine 
• 64897-42-3 phenyl 2,4-dinitrophenyl carbonate 

Downstream Products

• 22824-04-0 1,4-phenylene bis-phenylcarbamate 
• 23600-44-4 N-(4-aminophenyl)-4-methylbenzamide 

Relevant academic research and scientific papers

Concerted aminolysis of diaryl carbonates: Kinetic sensitivity on the basicity of the nucleophile, nonleaving group, and nucleofuge

The kinetics of the reactions of 4-methylphenyl, phenyl, and 4-chlorophenyl 2,4,6-trinitrophenyl carbonates (1, 2, and 3, respectively) with a series of anilines and secondary alicyclic (SA) amines has been carried out spectrophotometrically in 44 wt% ethanol-water, at 25.0°C, ionic strength 0.2 M. The BrAnsted plots (statistically corrected) for the reactions of carbonates 1-3 with anilines and SA amines were linear with slopes (βN) in the range of 0.69-0.78 and 0.45-0.48, respectively, attributed to a concerted mechanism. The negative values found for the sensitivity of log kN to the basicity of the nonleaving (βnlg) and leaving (βlg) groups are discussed. Anilines are more reactive than isobasic SA amines, probably because of the greater steric hindrance offered by the latter.

Anilinolysis of reactive aryl 2,4-dinitrophenyl carbonates: Kinetics and mechanism

The reactions of a series of anilines with phenyl 2,4-dinitrophenyl (1), 4-nitrophenyl 2,4-dinitrophenyl (2), and bis(2,4-dinitrophenyl) (3) carbonates are subjected to a kinetic investigation in 44 wt% ethanol-water, at 25.0 ± 0.1°C and an ionic strength of 0.2 M. Under amine excess pseudo-first-order rate coefficients (kobs) are obtained. Plots of kobs against free amine concentration at constant pH are linear, with slopes kN. The BrAnsted plots (log kN vs. anilinium pKa) for the anilinolysis of 1-3 are linear, with slope (β) values of 0.52, 0.61, and 0.63, respectively. The values of these slopes and other considerations suggest that these reactions are ruled by a concerted mechanism. For these reactions, the kN values follow the reactivity sequence: 3 > 2 > 1. Namely, the reactivity increases as the number of nitro groups attached to the nonleaving group increases. Comparison of the reactions of this work with the stepwise pyridinolysis of carbonates 1-3 indicates that the zwitterionic tetrahedral intermediate (T±) formed in the pyridinolysis reactions is destabilized by the change of its pyridino moiety by an isobasic anilino group. This is attributed to the superior leaving ability from the T± intermediate of anilines, relative to isobasic pyridines, which destabilize kinetically this intermediate. The kN values for the anilinolysis of carbonates 1-3 are similar to those found in the reactions of these carbonates with secondary alicyclic amines. With the kinetic data for the anilinolysis of the title substrates and 4-methylphenyl and 4-chlorophenyl 2,4-dinitrophenyl carbonates, a multiparametric equation is derived for log kN as a function of the pKa of the conjugate acids of anilines and nonleaving groups.

Novel and efficient one-pot synthesis of (aminophenyl)carbamic acid esters

A novel and efficient protocol is developed for the synthesis of various (aminophenyl) carbamic acid esters from the reduction and condensation of nitrophenyl isocyanate derivatives. The reaction takes place in various hydroxy derivatives such as alcohols or phenols under a hydrogen atmosphere using Raney nickel as catalyst. Products are obtained by a convenient one-pot synthesis with excellent yields and short reaction times.

Process for producing aryl carbamates

PCT No. PCT/JP98/00592 Sec. 371 Date Oct. 13, 1998 Sec. 102(e) Date Oct. 13, 1998 PCT Filed Feb. 13, 1998 PCT Pub. No. WO98/35936 PCT Pub. Date Aug. 20, 1998A process for producing an aryl carbamate of a high purity at a high yield by reacting a diaryl carbonate with an amine compound having one or more hydrogen atoms bonded to the N position in the presence of carboxylic acid(s) of the following general formulae (I): R1-COOH and/or (II): R2-COOH (wherein R1 represents an alkyl or cycloalkyl group having an alpha -positioned carbon atom bonded to only one hydrogen atom, an alkyl group having an alpha -positioned carbon atom bonded to no hydrogen atom, or an aryl or heterocyclic group, and R2 represents an alkyl group having an alpha -positioned carbon atom bonded to two or more hydrogen atoms).