Oxamide, hydrolysis

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-... 

Reaction LXXXIX. Hydrolysis of Nitriles to Amides. (B., 18, 355.)— When nitriles are heated with acids or alkalis they are hydrolysed to the corresponding acids passing intermediately through the amides. It is possible only in a few instances (e.g., oxamide) to stop the hydrolysis at this intermediate stage, unless alkaline hydrogen peroxide is employed, when the amide is obtained in almost theoretical yield. Both methods of hydrolysis are illustrated in the following preparations. 

It follows from the above that the explosive power of the compound is similar to that of TNT. The fact that it readily undergoes hydrolysis, forming picric acid and oxamide is a serious drawback and prevents its use as au explosive. 

In certain bicyclic and polycyclic thiadiazoles the ring can be hydrolytically cleaved to an o-diamine and sulfur dioxide. This process is a reversal of the reaction pathway involved in the synthesis of thiadiazoles from o -diamines and thionyl chloride or iV-sulfinylaniline under anhydrous conditions (see Section 4.26.5.1.1), and is analogous to, but much slower than, the hydrolysis of sulfurdiimides. In contrast to (1), which steam distilled without decomposition, steam distillation of [l,2,5]thiadiazolo[3,4-c][l,2,5]thiadiazole (21) produced only oxamide. Under milder conditions (75 °C, 12 h) a mixture of the diamine (22), oxamide and elemental sulfur was obtained (75JOC2749). Similar hydrolytic instability was observed in thiadiazole rings angularly joined to an anthraquinone (70RCR923) and ben-zofuroxan (78CPB3896). 

Hydrolysis of compound (87) gives 3,4-diamino-l,2,5-thiadiazole, oxamide and sulfur. In dilute ammonium hydroxide the yield of 3,4-diamino-1,2,5-thiadiazole is almost quantitative (75JOC2749). 

In this reaction parabanic acid resembles an amide oxamide yields oxalic acid and ammonia on hydrolysis —... 

The salts 28 and 29 (Y = NOg) were rapidly cleaved by aqueous base to the corresponding imidazolidones and iV-formyl compounds in high yield (equation 25) °. Had addition of a second hydroxide ion and double ring opening occurred in analogy to the strong-base hydrolysis of 5 (equation 12), an oxamide would have been formed. The lack of competition from this process may be attributable to base catalysis of the fragmentation of 86, a possibility which does not exist... 

Like formamides, homologous carboxamides may also be used for the acylation of organometallics unless the latter are sterically crowded. 2,6-Dichlorophenyllithium and other 2,6-disubstituted aryllithiums can only combine with dimethylformamide. If tetramethyloxalamide is treated with one equivalent of organolithium prior to hydrolysis, a 2-oxocaui>oxamide is obtained, with two equivalents symmetrical v/c-diketones. ... 

Pure (192) is a white crystalline solid resembling naphthalene in its physical properties. Its high degree of symmetry is reflected in the simplicity of its i.r. spectrum. Hydrolysis yields successively 3,4-diamino-l,2,5-thiadiazole, oxamide, and sulphur. ... 

---