Carbobenzoxy-L-asparagine

Carbobenzoxy-L-asparagine (obtained from the Aldrich Chemical... 

Aromatic compounds, carboxylation of, 28 L-Asparagine, carbobenzoxy- [L-Asparagine, -[(phenylmethoxy[carbonyl]-], 89 L-Asparagine, IP -(trifluoroacetyl)-, 125 L-ASPARAGINYL-L-LEUCINE, CARBOBENZOXY-, METHYL ESTER [L-LEUCINE, A -[AT -[(PHENYLMETH-OXY)CARBONYL] -L-ASPAR-GINYL] -, METHYL ESTER, 88 2-Asp.Gly-OEt [Glycine, N- [Al -[(phenyl-methoxy)carbonyl] -L-asparaginyl] -, ethyl ester], 93... 

A soln. of dicyclohexylcarbodiimide in pyridine added portionwise with stirring at 16-20° during 30 min. to a soln. of carbobenzoxy-L-asparagine in pyridine, and the product isolated after not longer than 3 hrs. at this temp. carbo-benzoxy-j -cyano-L-alanine. Y 78%. F. e. s. C. Kessler and H. Ratzkin, J. Org. Ghem. 26, 3356 (1961). 

A soln. of carbobenzoxy-L-asparagine methyl ester in pyridine treated at —10 to 0° with POGI3 in methylene dichloride -> crude j -cyano-L-a-carbobenzoxy-alanine methyl ester. Y 75-83%.—In the synthesis of asparaginylpeptides, the carbamyl group may be protected by conversion to a nitrile group. E. s. B. Liberek, Ghem. Ind. 1961, 987. 

A soln. of a-benzyl -butyl carbobenzoxy-L-asparaginate in ethanol-water treated with 1 N NaOH, and stirred 15 min. at room temp. crude j -tert-butyl carbobenzoxy-L-asparaginate. Y 95%. R. Schwyzer and H. Dietrich, Helv. 4, 2003 (1961) prevention of racemization s. I. Photaki, Am. Soc. 85, 1123 (1963). 

Arylphosphonic acid derivatives, 58, 137 Arylphosphonic dichlorides, 58, 136 Aryltetrachlorophosphoranes, 58, 137 L-Asparagine, carbobenzoxy-, 56, 89 L-Asparagine, NJ-(tnfluoroacetyl)- 56, 125 L ASPARAGINYL-L-LEUCINE, CARBOBENZOXY-,METHYL ESTER, 56, 88 Z-Asp Gly-OEt, 56, 93 (l-Azido-3,3-dimethoxy-l-propenyl)ben-zene, 57, 84... 

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