97984-63-9

Usage

Chemical Properties

White solid

Upstream product

• 60-18-4 L-tyrosine 
• 100-51-6 benzyl alcohol 
• 104-15-4 toluene-4-sulfonic acid 
• 556-02-5 ?Tyr 
• 42406-77-9 L-tyrosine benzyl ester 

Downstream Products

• 3061-91-4 L-valyl-L-tyrosine 
• 75958-14-4 Aspartyl-valyl-tyrosine 
• 75957-55-0 N^α-t-butoxycarbonyl-N^ε-benzyloxycarbonyl-L-lysyl-β-benzyl-L-aspartyl-L-valyl-L-tyrosine benzyl ester 
• 75957-57-2 N^α-benzyloxycarbonyl-N^ω-nitro-L-arginyl-N^α-benzyloxycarbonyl-L-lysyl-β-benzyl-L-aspartyl-L-valyl-L-tyrosine benzyl ester 

Relevant academic research and scientific papers

Phosphorylation of Tyrosine and Tyr-Thr-Lys Tripeptide with Cyclohexylmethyl- and (Deuteromethyl)phosphonochloridates

Abstract: Methods for phosphorylation of tyrosine and Tyr-Thr-Lys tripeptide with cyclohexylmethyl(deuteromethyl)phosphonochloridates have been developed. These products can be used as reference compounds in the analysis of blood plasma of patients presumably exposed to cyclohexylmethylphosphonofluoridate (cyclosarin) action. Conditions for the separation and purification of the synthesized intermediates by means of chromatography have been determined and optimized, allowing high-purity phosphorylated products at the final stage of the synthesis.

One-step preparation of enantiopure l- or d-amino acid benzyl esters avoiding the use of banned solvents

The enantiomers of amino acid benzyl esters are very important synthetic intermediates. Many of them are currently prepared by treatment with benzyl alcohol and p-toluenesulfonic acid in refluxing benzene or carbon tetrachloride, to azeotropically remove water, and then precipitated as tosylate salt by adding diethyl ether. Here, we report a very efficient preparation of eight l- or d-amino acid benzyl esters (Ala, Phe, Tyr, Phg, Val, Leu, Lys, Ser), in which these highly hazardous solvents are dismissed using cyclohexane as a water azeotroping solvent and ethyl acetate to precipitate the tosylate salt. With some work-up modifications and lower yield, the procedure can be applied also to methionine. Chiral HPLC analysis shows that all the benzyl esters, including the highly racemizable ones such as those of phenylglycine, tyrosine and methionine, are formed enantiomerically pure under these new reaction conditions thus validating the solvents replacement. Contrariwise, toluene cannot be used in place of benzene or carbon tetrachloride because leading to partially or totally racemized amino acid benzyl esters depending on the polar effect of the amino acid α-side chain as expressed by Taft’s substituent constant (σ*).

Esterification of unprotected a-Amino acids in ionic liquids as the reaction media

Ionic liquid 1,3-dimethylimidazolium methanesulfonate was used to prepare a-amino acids benzylic esters from unprotected amino acids and benzyl chloride. Esterification of several amino acids was achieved with satisfactory yields: by-products can be removed by a simple work-up procedure to afford the pure product. The described method is simple, mild, rapid and save.

Primary amino acid lithium salt as a catalyst for asymmetric Michael addition of isobutyraldehyde with β-nitroalkenes

Phenylalanine lithium salt was found to be an effective catalyst for asymmetric Michael addition of isobutyraldehyde with β-nitroalkenes to give quaternary carbon-containing nitroalkanes. The Royal Society of Chemistry.