Barbituric acids carbodiimides

In the reaction of carbodiimides with barbituric acids 421 in DMSO at 150 °C, insertion into the C—H bond occurs with formation of 5-diaminomethylenebarbiturates 422. ... 

Six-membered ring heterocycles 708 are obtained in the reaction of carbodiimides with malonyl chloride. Hydrolysis of the dichlorodihydropyrimidine-diones affords barbituric acid derivatives. ... 

Reaction of carbodiimides with malonates or acetoacetic esters affords the insertion products. For example, reaction of barbituric acids 137 and DCC in DMSO at 150 °C gives the C-H insertion products 138 °. 

Photochemical a-addition of a nitrene to 1-isocyano sugars leads to the carbodiimide which adds water yielding glycosylurea or malonic acid to form potential glycosyl-barbiturate synthons [57] (Scheme 29). 

Photochemical addition of a nitrene to the isonitrile (6) led to the carbodiimide (7), which added water to give urea (8) and malonic acid to give the potential glycosyl barbiturate synthon (9)... 

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