Glycine benzyloxycarbonyl

The same reagents can be used to form amides from carboxylic acids and amines, a method which is applicable to peptide synthesis. Condensation of A-benzyloxycarbonyl-L-phenylalanine and ethyl glycinate hydrochloride gave an 85% yield of purified dipeptide. 

N-[N-(benzyloxycarbonyl)-L-aspart-l-oyl-(L-alanyl-L-threonyl-L-leucyl-L-alanine p-nitrobenzyl ester)-4-oyl]-N-[N-(benzyloxycarbonyl)-L-aspart-l-oyl-(L-alanyl-L-threonyl-L-leucyl-L-alanyl-L-serine p-nitrobenzyl ester)-4-oyl]-N-[N-(benzyloxycarbonyl)-L-aspart-1 -oyl-(glycine ethyl ester)-4-oyl -N-[N-(benzyloxycarbonyl)-L-aspart-l-oyl-(glycyl-L-serine methyl ester)-4-oyl]-... 

D. M. Lambert, G. K. E. Scriba, J. H. Poupaert, P. Dumont, Anticonvulsant Activity of Ester- and Amide-Type Lipid Conjugates of Glycine and V-Benzyloxycarbonyl Glycine , Eur. J. Pharm. Sci. 1996, 4, 159-166. 

Cl ii X H5Ca 0 N C00CH3 N-Benzyloxycarbonyl- 2-chlor-glycin- metkylester 0 OH II x HsCi O N COOCHj + soc iz, ch2ci2 5... 

Butyllithium, 56 Organozinc reagents, 220 3-Trimethylsilyl-l-propyne, 329 Cross-coupling of alkyl + vinyl groups Iodosylbenzene, 151 Methyl N-benzyloxycarbonyl-a-chloro-glycinate, 186... 

Functional group protection. The NH— group in proline is protected by acylation in the usual Schotten-Baumann manner with benzyl chloroformate to yield the benzyloxycarbonyl derivative (42). Correspondingly the —C02H group in glycine is protected by esterification in ethanol to form the ethyl ester, obtained as the hydrochloride (43) under Fischer-Speier conditions. 

Although CDI was applied as early as 1972 as reagent for the esterification of starch and dextran, it has only scarcely been used up to now. Its renaissance during the last few years may be due to the fact that it became an affordable commercially available product. Among the first attempts for the esterification of polysaccharides via CDI is the binding of amino acids onto dextran. Besides CDI, -(thiocarbony diimidazole can be utilised to obtain the corresponding imidazolide [198]. The amino acids bound via this path are glycine, L-leucine, L-phenylalanine, L-histidine and L-alanyl-L-histidine. They are protected with N-trifluoroacetyl, N-benzyloxycarbonyl... 

Related Reagents. l-Benzoyl-2-r-butyl-3,5-dimethyl-4-imi-dazolidinone (2S,4S)-3-Benzoyl-2-/-butyl-4-methyl-1,3-oxazo-lidin-5-one N-Benzyloxycarbonyl-t-serine p-Lactone N-r-Buto-xycarbonyl-N-methylaminomethyllithium (R)-2-r-Butyl-6-methyl-4H-l, 3-dioxin-4-one N, N-Diethylaminoacetonitrile Ethyl N-(Diphenylmethylene)glycinate Ethyl Isocyanoacetate Methyl ot-Phenylglycinate... 

Bromomethyl-5-methylisoxazole 231 was exploited in reactions with enantiopure benzyloxycarbonyl-protected glycine equivalents 232 for the synthesis of a-substituted and a,a-disubstituted amino acids 234 through hydrolysis of 233 (Scheme 54) <2004T7679>. 

Dibenzyl dicarbonate offers some advantages in the preparation of N-benzyloxycarbonyl amino-acids, compared to the widely used benzyl chloroformate. For example, preparation of dipeptide-free N-benzyloxycarbonyl glycine is easily achieved under standard pH-stat conditions if the pH is carefully regulated. 

Abbreviations Ala, alanine Leu, leucine BLAsp, /3-benzyl L-aspartate BLGlu, 7-benzyl L-gluta-mate MLGlu, 7-methyl L-glutamate Val, valine lie, isoleucine Gly, glycine Pro, proline Bu, butyl Et, ethyl Bzl, benzyl Me, methyl Z, benzyloxycarbonyl Nps, (o-nitrophenyl)sulphenyl. 

Synthesis of N-benzyloxycarbonyl-lysine-glycine methyl ester. 

N-(Benzyloxycarbonyl)glycine 576 Benzyl chloroformate (17 g) and 4N-sodium hydroxide solution (25 ml) are added separately but simultaneously, slowly and with stirring, within 20-25 min to an ice-cooled solution of glycine (7.5 g) in 2N-sodium hydroxide solution (50 ml). The mixture is then stirred for a further 10 min, whereafter it is extracted with ether. The aqeuous phase is acidified to Congo Red by concentrated hydrochloric acid under icecooling. The precipitated amide acid is filtered off, washed with a little water, dried in the air, and recrystallized from chloroform. The yield is 18-19 g and the m.p. 120°. 

HsC2OOC-CH2-NH—CO-CH-(CH2)2-CO-NH 1 1 H5C6-CH2-O-CO-NH H5ce-NH 50%ige H3C-COOH, MnOa 25 0,5 N-Benzyloxycarbonyl-a-L-glutamyl- glycin-ethylester 82 426... 

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