1219-32-5

Upstream product

• 98-88-4 benzoyl chloride 
• 824-78-2 4-nitrophenol sodium salt 
• 77750-05-1 4-methoxy-thiobenzoic acid S-(4-nitro-phenyl ester) 
• 1849-36-1 para-nitrobenzenethiol 
• 67864-01-1 substituted benzenethiol 
• 65-85-0 benzoic acid 

Downstream Products

• 2866-82-2 N-(4-chlorophenyl)benzamide 
• 7472-54-0 N-(p-methoxyphenyl)benzamide 
• 138-42-1 p-nitrobenzenesulfonic acid 
• 65-85-0 benzoic acid 
• 776-75-0 N-benzoylpiperidine 
• 1849-36-1 para-nitrobenzenethiol 
• 13735-81-4 1-styrenyloxytrimethylsilane 
• 39248-99-2 S-(4-nitrophenyl) 4-methylbenzothioate 
• 120-46-7 1,3-diphenylpropanedione 
• 766-76-7 benzoate 
• 45797-13-5 4-nitrophenylthiolate 
• 57238-77-4 4-benzoyl-1-piperazinecarboxaldehyde 
• 13754-38-6 N-Benzoylpiperazine 
• 1468-28-6 4-benzoylmorpholine 

Relevant academic research and scientific papers

" Mediator Methodology" for the Synthesis of Peptides in a Two-Polymeric System

Abstract: A novel methodology is described for a potential automated self-controlled synthesis of peptides.The method is based on transferring an N-protected amino acid from one insoluble polymer (donor) such as a polymeric o-nitrophenyl ester (a "bank" of active ester) to an insoluble polymer-bound amino acid (acceptor),with the aid of a soluble mediator molecule (shadchan)2 The method gives high yields of pure peptides by garanteeing stoichiomeric supply of the active ester and allowing self monitoring.When the polymer-bound (dimethylamino)pyridinium salts, the condensation reaction was expended to also include sulfonation and particularly phosphorylation reactions.

Ethyl 2-(tert-butoxycarbonyloxyimino)-2-cyanoacetate (Boc-Oxyma) as coupling reagent for racemization-free esterification, thioesterification, amidation and peptide synthesis

Here we report the synthesis and utility of ethyl 2-(tert- butoxycarbonyloxyimino)-2-cyanoacetate (Boc-Oxyma) as an efficient coupling reagent for racemization-free esterification, thioesterification, amidation reactions and peptide synthesis that uses equimolar amounts of acids and alcohols, thiols, amines or amino acids, respectively. Its application to solid phase as well as solution phase peptide synthesis is also demonstrated and a mechanistic investigation is discussed. Boc-Oxyma is similar to the well known coupling agent COMU {1-[1-cyano-2-ethoxy-2-oxoethylideneaminooxy)- dimethylaminomorpholino] uronium hexafluorophosphate} in terms of its high reactivity and mechanism of action. However, it is not only much easier to prepare, but also to recover and reuse, thereby generating far less chemical waste.

Aminolysis of S-4-nitrophenyl X-substituted thiobenzoates: Effect of nonleaving-group substituents on reactivity and mechanism

A kinetic study is reported for aminolysis of S-4-nitrophenyl X-substituted thiobenzoates 3a-g in 80 mol % H2O/20 mol % DMSO at 25.0 ± 0.1 °C. Thiol esters 3a-g are 7.8-47.6 fold more reactive than the corresponding oxygen esters (i.e., 4-nitrophenyl X-substituted benzoates 1a-g). Such reactivity order appears to be in accordance with the expectation that 4-nitrothiophenoxide in 3a-g is a better nucleofuge than 4-nitrophenoxide in 1a-g since the former is 2.64 pKa units less basic than the latter. Hammett plot for the reactions of 3a-g exhibit poor correlation coefficients (R2 = 0.977-0.986) with negative deviation by substrates possessing an electrondonating group (EDG), while the Yukawa-Tsuno plots result in excellent linear correlation (R2 = 0.995-0.997) with ? = 0.93-1.23 and r = 0.57-0.67, indicating that the negative deviation shown by substrates possessing an EDG is caused by ground-state stabilization through resonance interactions but not due to a change in ratedetermining step upon changing the nonleaving-group substituent X. The p value increases as the incoming amine becomes more basic and more reactive, indicating that the RSP is not operative in the current reactions.

CsF-Celite, an efficient solid state reagent for the syntheses of thioesters and thioethers

Coupling reactions of a number of aliphatic, aromatic, and heterocyclic compounds bearing an acidic hydrogen atom attached to sulfur, with alkyl, acyl, benzyl, or benzoyl halides in acetonitrile with cesium fluoride-Celite are described. This procedure is convenient, efficient, and practical for the preparation of thioethers and thioesters. Springer-Verlag 2005.

An alternative approach towards the syntheses of thioethers and thioesters using CsF-Celite in acetonitrile

It has been found that syntheses of thioethers and thioesters of aliphatic, aromatic and heterocyclic compounds, bearing thiol groups, can be accomplished with alkyl, acyl, benzyl or benzoyl halides in acetonitrile and cesium fluoride-Celite. In this manner, compounds like ethanethiol, 1-pentanethiol, thiophenol, 4-methoxythiophenol, 4-nitrothiophenol, and 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, and 2-mercapto-2-thiazoline can be successfully alkylated, acylated, benzylated or benzoylated. This procedure is convenient, efficient and practical for the preparation of thioethers and thioesters.

1H, 13C and 17O NMR study of substituent effects in 4-substituted phenylthiol esters

The 1H and 13C NMR spectra of 4-substituted phenylthiol acetates, benzoates and cinnamates and the 17O NMR spectra of a few thiol acetates were measured. The 13C chemical shifts of C-1 of the thiol esters when correlated with appropriate substituent-induced chemical shifts (SCS) of monosubstituted benzenes reveal an enhancement of substituent effect at C-1. Several good dual substituent parameter (DSP) correlations of 13C chemical shifts with σ1 and σR parameters were obtained for the carbons para to the substituent and the carbonyl carbons of all the three series of thiol esters display inverse substituent effects, indicating π-polarization of the thiol ester functionality by the dipole of the substituent. John Wiley & Sons Ltd.

Sulfide Oxidation and Oxidative Hydrolysis of Thioesters by Peroxymonosulfate Ion

Peroxymonosulfate ion, HSO5-, as OXONE, in aqueous MeCN readily converts aryl thiobenzoates, XC6H4CO*SC6H4Z (X = p-OMe, p-Me, H, p-Cl, p-CN; Z = p-OMe, p-Me, H, m-OMe, p-Cl, m-Cl, p-NO2) into carboxylic and sulfonic acids.Reactions are second order and have small substituent effects, with ρ ca. -0.6 based on ?m and ?p substituent parameters, but rates increase markedly with increasing water content in aqueous MeCN and entropies of activation are negative.The initial step is very similar to the oxidation of methyl aryl sulfides by HSO5- which has similar solvent and substituent effects.Enthalpies of activation are much lower for oxidation of the sulfides than of the corresponding esters but entropies of activation are similar.

Kinetics and Mechanism of the Aminolysis of S-Phenyl Thiobenzoates

Kinetic studies on the nucleophilic substitution reaction of S-phenyl thiobenzoates with anilines have been carried out at 55.0 deg C.Effects of substituents in the nucleophile(X), substrate(Y) and leaving groups(Z) are analyzed in terms of Hammett's and Broensted's coefficients, ρi and βi and cross-interaction constants ρij and βij where i and j denote X, Y or Z.The sign of ρXZ (or βXZ) is positive, and accordingly, the transition state(TS) variations with the substituents are consistent with those predicted by the potential energy surface diagram; the magnitude of ρx(βx) and ρxy decreases with a better leaving group, and that of ρz and βz decreases with a stronger nucleophile leading to an earlier TS, in agreement with a normal Hammond effect.The larger magnitudes of ρXY, ρYZ and βXZ suggest that the reaction proceeds by an associative SN2 mechanism.A greater kH/kD value (1.0) is observed with deuterated aniline nucleophiles for a stronger nucleophile and a better leaving group, supporting the earlier TS proposed on the basis of the cross-interaction constants.The inverse secondary kinetic isotope effects obtained preclude involvement of any four-center TS or base catalysis by aniline.