CAS No 556-50-3 , 2-[(2-aminoacetyl)amino]acetic acid

Title: N-Glycylglycine
CAS Registry Number: 556-50-3
Molecular Formula: C4H8N2O3
Molecular Weight: 132.12
Percent Composition: C 36.36%, H 6.10%, N 21.20%, O 36.33%
Line Formula: NH2CH2CONHCH2COOH
Literature References: The simplest of all peptides. Prepn from 2,5-diketopiperazine: Schott et al., J. Org. Chem. 12, 490 (1947); Greenstein, Winitz, Chemistry of the Amino Acids vol. 2, (New York, 1961) p 803. From tritylglycylglycine: Zervas et al., J. Am. Chem. Soc. 78, 1359 (1956). From phthalylglycylglycine: Sheehan, Frank, ibid. 71, 1856 (1949). From the dicyclohexylamine salt of trifluoroacetylglycylglycine: Weygand, Reiher, Ber. 88, 26 (1955).
Properties: Crystals from dil alc. Crystal shape described as small tetrahedral leaves with a lustrous ball in center. Dec 262-264°. pK1￠ 3.12; pK2￠ 8.17. Heat of combustion: 472.4 kcal/mole. Soluble in hot water; slightly sol in ethanol. Practically insol in ether.
pKa: pK1￠ 3.12; pK2￠ 8.17
 
Derivative Type: Hydrochloride monohydrate
Molecular Formula: C4H8N2O3.HCl.H2O
Molecular Weight: 186.59
Percent Composition: C 25.75%, H 5.94%, N 15.01%, O 34.30%, Cl 19.00%
Properties: Crystals from water + ethanol.
 
Derivative Type: Ethyl ester hydrochloride
Properties: Crystals from abs ethanol, dec 182°.
 
Use: In the synthesis of more complicated peptides.