Glycine ethanolamine

An alternative sequence utilized 2-oxazolidone, which was readily synthesized from urea and ethanolamine, as the glycine equivalent. Subsequent treatment with phosphorous acid and formaldehyde produced iV-phosphonomethyl-2-oxazolidone 12 (16). Upon hydrolysis, and loss of CO2,12 provided the related derivative, iV-phosphonomethylethanolamine 13, which was oxidized at high temperature with a variety of metal catalysts including cadmium oxide (16) or Raney copper (17) to give GLYH3, after acidification. A similar oxidation route has also been reported starting from iV-phosphonomethy 1-morpholine (18). 

The oxidative dehydrogenation of ethanolamine to sodium glycinate in 6.2 M NaOH was investigated using unpromoted and chromia promoted skeletal copper catalysts at 433 K and 0.9 MPa. The reaction was first order in ethanolamine concentration and was independent of caustic concentration, stirrer speed and particle size. Unpromoted skeletal copper lost surface area and activity with repeated cycles but a small amount of chromia (ca. 0.4 wt%) resulted in enhanced activity and stability. 

The oxidative dehydrogenation of aminoalcohols has received little attention in the non-patent literature. Yang et al. (7) recently made a kinetic study of the dehydrogenation of ethanolamine to glycine salts... 

Chitwood (2) found that copper compounds exhibited only a short period of maximum catalytic activity for the dehydrogenation of ethanolamine to glycine salt. In this study, the catalytic activity of a skeletal copper catalyst was tested in repeated use. The catalyst used was prepared by selectively leaching CuAl2 particles in a 6.1 M NaOH solution at 293 K for 24 hours. Figure 1 shows the profiles of hydrogen evolved versus reaction time. 

Figure 3 Comparison of first order plots for the formation of hydrogen and of glycine salt during ethanolamine dehydrogenation over unpromoted skeletal copper under standard conditions.

Add to the particle suspension a quenching molecule (such as glycine, ethanolamine, or Tris) to give a final concentration of 0.2 M. The blocking agent will couple to any remaining aldehyde-reactive sites. 

Note Some protocols do not call for a reduction step. As an alternative to reduction, add 50 pi of 0.2 M lysine in 0.5 M sodium carbonate, pH 9.5 to each ml of the conjugation reaction to block excess reactive sites. Block for 2 hours at room temperature. Other amine-containing small molecules may be substituted for lysine—such as glycine, Tris buffer, or ethanolamine. 

Published work since then has largely concentrated on two specific reactions, the conversion of ethanolamine to glycinate e.g. (2, 3)... 

In the synthesis of fatty acids the acetyl irnits are condensed and then are reduced to form straight hydrocarbon chains. In the oxo-acid chain elongation mechanism, the acetyl unit is introduced but is later decarboxylated. Tlius, the chain is increased in length by one carbon atom at a time. These two mechanisms account for a great deal of the biosynthesis by chain extension. However, there are other variations. For example, glycine (a carboxylated methylamine), under the influence of pyridoxal phosphate and with accompanying decarboxylation, condenses with succinyl-CoA (Eq. 14-32) to extend the carbon chain and at the same time to introduce an amino group. Likewise, serine (a carboxylated ethanolamine) condenses with... 

Crans, D.C. and P.K. Shin. 1994. Characterization of vanadium(V) complexes in aqueous solutions Ethanolamine- and glycine-derived complexes. J. Am. Chem. Soc. 116 1305-1315. 

Poly(carboxyethyl 3-aminocrotonate) modified by fS-alanine Poly(carboxyethyl 3-aminocrotonate) modified by ethanolamine Poly(carboxyethyl 3-aminocrotonate) modified by glycine Poly(carboxyethyl 3-aminocrotonate) modified by lysine Poly(carboxyethyl 3-cyclohexylaminocrotonate)... 

The rearrangement products derived from aromatic and non-aromatic heterocyclic amines crystallize readily from the lower alcohols. Unlike those of many of the A-substituted glycosylamines, the crystals are not solvated. On the other hand, the ketose derivatives of aralkyl- and alkyl-amines, such as 2-phenylethylamine, ethanolamine, diethanolamine, glycine ethyl ester, and phenylalanine (see Table II), are hydrated or alcoholated, or both, and are difficult to isolate in pure crystalline form. The crystals which have been isolated were hygroscopic. Alcohols, aqueous alcohols, and water are the most commonly used solvents for crystallization. Acetone, ether, or benzene have been added to the alcoholic media in order to increase the yield of crystalline compound. The use of solvents that contain peroxides promotes decomposition of the crystals during storage. ... 

The pathways for the formation of oxalate from glycine, ethanolamine, and ascorbic acid, are shown in Figure 10.41. Apparently, oxalate has no function in the body, nor is It catabolized to carbon dioxide. Oxalate occurs in plants as sodium... 

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