33857-84-0

Upstream product

• 4070-48-8 L-Valine methyl ester 
• 33861-70-0 (S)-2-Benzyloxycarbonylamino-4-methylsulfanyl-thiobutyric acid S-pyridin-2-yl ester 
• 6306-52-1 L-valine methylester hydrochloride 
• 84889-07-6 (S)-2-Benzyloxycarbonylamino-4-methylsulfanyl-butyric acid; compound with dicyclohexyl-amine 
• 72-18-4 L-valine 
• 63-68-3 L-methionine 
• 501-53-1 benzyl chloroformate 
• 1152-62-1 Cbz-Met-OH 
• 2483-42-3 benzyloxycarbonyl-L-methionine p-nitrophenyl ester 
• 3392-01-6 N-carbobenzoxy-L-methionine N-succinimidoyl ester 
• 4841-70-7 N-carbobenzoxy-L-methionine pentachlorophenyl ester 
• 17543-51-0 N-carbobenzoxy-L-methionine pentafluorophenyl ester 

Relevant academic research and scientific papers

Recyclable hypervalent iodine(III) reagent iodosodilactone as an efficient coupling reagent for direct esterification, amidation, and peptide coupling

A hypervalent iodine(III) reagent plays a novel role as an efficient coupling reagent to promote the direct condensation between carboxylic acids and alcohols or amines to provide esters, macrocyclic lactones, amides, as well as peptides without racemization. The regeneration of iodosodilactone (1) can also be readily achieved. The intermediate acyloxyphosphonium ion C from the activation of a carboxylic acid is thought to be involved in the present esterification reaction.

KINETICS OF THE ALKALINE HYDROLYSIS OF SEVERAL N-BENZYLOXYCARBONYLDIPEPTIDE METHYL AND ETHYL ESTERS

The reaction rates of the alkaline hydrolysis of synthesized N-protected dipeptide methyl and ethyl esters were studied systematically.From the kinetic data the energies of activation, the pre-exponential factors and the reference values at 40 deg C were calculated.The rate of hydrolysis shows to be strongly dependent on the C-terminal amino acid in the sequence Gly >> Ala/Met/Phe > Leu >> Val/Pro.Surprisingly the N-terminal amino acid also exerts an effect, but in a different sequence.N-Terminal Phe in particular shows a relative accelerating effect.Remarkable is the significantly faster ester hydrolysis of glycine containing dipeptide ethyl esters in ethanol/water compared to the corresponding methyl esters in methanol/water.

Kinetic Studies in Peptide Chemistry. Coupling, Racemization, and Evaluation of Methods Useful for Shortening Coupling Time

Kinetic studies were carried out on N-protected methionine and glycylmethionine active esters to determine the racemization rate constants with triethylamine and the coupling rate constants with valine methyl ester.In contrast to cysteine dipeptide active esters, which racemize through an enolization mechanism, the methionine dipeptide active esters racemize through the usual 5(4H)-oxazolone route.The role of sulfur in the side chain is discussed.The time required for coupling a given percentage (e.g., 99 percent) of the amine component can be significantly reduced by using an excess of the active ester.This method is evaluated quantitatively for second-order kinetics.