Oxamic acid, oxamide

Following slow dissolution into the soil solution, oxamide undergoes stepwise hydrolysis to Hberate ammonia. Oxamic acid is formed in the first... 

Anodic oxidation of 6- and 7-pteridone, using electrolysis at a controlled potential, gave pteridine-6,7-dione in 95-100% yield.409 Under controlled-potential electrolysis conditions pteridine-6,7-dione is oxidized to the bridgehead diol, which undergoes rearrangement, further oxidation, and hydrolysis, yielding tetraketopiperazine, oxamide, urea, oxamic acid, ammonia, formaldehyde, formic acid, and C02-... 

COOH Oxalic acid COOH Oxamic acid CO—NH2 Oxamide... 

Another reaction by which both oxamic acid and oxamide may be prepared is by heating the ammonium salt of oxalic acid. The reaction takes place in two steps. Firsts by the loss of one molecule of water the ammonium salt of oxamic acid is formed. Second, by the loss of another molecule of water, this is converted into oxamide, as follows ... 

This process is supported by the evidence that the yields of amino acids are significant at high temperatiu s such as 90 °C. The presence of Mg enhances this process through the stabilization of oxamic acid caused by the complex formation between oxamic add and Mg and hence the yields of amino adds from ammonium oxalate increase remarkably in the presence of 0.1 M MgCl2. Here, the thermal conversion of soUd ammonium oxalate to oxamide via oxamic acid is weU known. 

Although further investigation is necessary, we assume nucleic acid bases might be formed by UV irradiation of oxamic acid or decomposition products such as oxamide since yields of nucleic acid bases in the presence of oxamic acid were somewhat higher than those in the presence of ammonium oxalate (cf.. Table 1). 

Oxamide, discovered by J. C. D. BauhoP by the action of ammonia on ethyl oxalate, was obtained by Dumas by distilling ammonium oxalate. The mono-amide, oxamic acid, was discovered by Balard by heating acid... 

Oxamides, dialkyl oxalate esters, and oxamic add esters can be prepared by Pd-catalyzed double carbonylation of secondary amines and alcohols via incorporation of two molecules of carbon monoxide into amines and/or alcohols. Pd-catalyzed double carbonylation reactions of amines in the absence or presence of alcohol were reported earlier to give ox-amides and oxamic acid ester.t i t Selective formation of oxamides has been achieved by double carbonylation of secondary amines in the presence of iodide ion and dioxygen catalyzed by Pd(OAc>2 (Eq. 

The mechanism for the formation of oxamides was proposed as shown in Scheme Pd-catalyzed cross double carbonylation of secondary amines and alcohols to give oxamic acid esters together with the formation of earbamate, mea, and oxamide was also developed by employing Cul as a eoeatalyst. In a stoichiometric reaction, oxamate can be formed selectively by treatment of PdCl2(MeCN)2 with a secondary amine and alcohol under CO (Eq. 22). ... 

Dipole Moments. The dipole moment of thioformamide (p, = 4.01 D) has been calculated from Stark effect measurements on its microwave spectrum. Dipole-moment measurements of simple aliphatic and alicyclic dithio-acids indicated that these exist mainly in the s-cts-form (530) rather than the s-trans (531). The conformations of a series of thio-oxamides, dithio-oxamides, and ethyl thio-oxamates have been determined on the... 

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