64897-42-3

Upstream product

• 51-28-5 2,4-Dinitrophenol 
• 1885-14-9 phenyl chloroformate 

Downstream Products

• 102-09-0 bis(phenyl) carbonate 
• 51-28-5 2,4-Dinitrophenol 
• 20350-26-9 2,4-dinitrophenolate 
• 6465-00-5 (4-Amino-phenyl)-carbamic acid phenyl ester 
• 622-46-8 carbamic acid phenyl ester 
• 4930-03-4 phenyl N-phenylcarbamate 
• 20950-96-3 (4-methoxyphenyl)carbamic acid phenyl ester 
• 33275-26-2 N-(4-methylphenyl)-O-phenyl carbamate 
• 50699-51-9 O-phenyl N-(3-methoxyphenyl)carbamate 
• 405905-06-8 phenyl (3-acetylphenyl)carbamate 

Relevant academic research and scientific papers

Nucleophilic substitution reactions of phenyl y-substituted-phenyl carbonates with butane-2,3-dione monoximate and 4-chlorophenoxide: Origin of the α-effect

Second-order rate constants have been measured spectrophotometrically for the reactions of phenyl Ysubstituted- phenyl carbonates 7a-g with butane-2,3-dione monoximate (Ox-) in 80 mol % H2O/20 mol % DMSO at 25.0 ± 0.1 °C. The α-nucleophile Ox- is 53-95 times more reactive than the corresponding normalnucleophile 4-ClPhO- toward 7a-g, indicating that the α-effect is operative. The magnitude of the α-effect (e.g., the kOx/k4-ClPhO ratio) is independent of the electronic nature of the substituent Y. The cause of the α- effect for the reactions of 7a-g has been suggested to be ground-state (GS) effect rather than transition-state (TS) stabilization through a six-membered cyclic TS, in which Ox- behaves a general acid/base catalyst. This idea is further supported by the result that OH- exhibits negative deviation from the linear Bronsted-type plot composed of a series of aryloxides, while Ox- deviates positively from the linearity. Differential solvation of the GS of Ox- and 4-ClPhO- has been suggested to be responsible for the α-effect exerted by Ox-.

Kinetic investigation of the phenolysis of phenyl 4-nitrophenyl and phenyl 2,4-dinitrophenyl carbonates

The reactions of phenyl 4-nitrophenyl carbonate (PDNPC) and phenyl 2,4-dinitrophenyl carbonate (PDNPC) with a homogeneous series of phenoxide anions are subjected to a kinetic investigation in water at 25.0 °C, ionic strength 0.2 mol dm-3 (KCl). Under phenoxide or total phenol excess over the substrate all these reactions obey pseudo first-order kinetics and are first order in phenoxide. The Bronsted-type plots for the nucleophilic rate constants are linear with slopes 0.61 and 0.49 for the phenolysis of PNPC and PDNPC, respectively. The magnitude of these slopes and the absence of curvature in the Brnsted plot at pKa = 7.1 for the PNPC reactions are consistent with concerted mechanisms (one step) for both reaction series. PDNPC is more reactive than PNPC toward phenoxide nucleophiles; this can be explained by the presence of a second nitro group in PDNPC, which (i) leaves its carbonyl carbon more positively charged than that of PNPC, making the former a better electrophile, and (ii) makes 2,4-dinitrophenoxide a better leaving group than 4-nitrophenoxide. The larger nucleophilic rate coefficients found in this work relative to those obtained in the concerted phenolysis of 4-nitrophenyl and 2,4-dinitrophenyl methyl carbonates is explained by a stronger electron withdrawal from PhO compared to MeO. Comparison of the concerted phenolysis of PNPC with the stepwise reactions of quinuclidines with the same substrate indicates that substitution of a quinuclidino group in a zwitterionic tetrahedral intermediate by a phenoxy group greatly destabilises the intermediate.