摘要：

The reactions of a variety of acids (in particular, mono- and diesters of phosphoric acid) with a group of carbodiimides in the presence of tertiary bases have been studied. The carbodiimides chosen were dicyclohexyl-, di-p-tolyl- and di-t-butyl-carbodiimides and the bases used were pyridine and tri-n-butylamine. The mechanism of reactions of carbodiimides with acids is discussed in the light of these findings. The formation of diesters of phosphoric acid by the reaction of a monoalkyl phosphate with dicyclohexylcarbodiimide in the presence of an alcohol has been examined and it has been demonstrated that this synthesis can occur by two discrete mechanisms. The present studies have resulted in new and improved procedures for the synthesis of ribonucleoside-2′,3′ cyclic phosphates, diesters of pyrophosphoric acid, nucleoside-5′ monoalkyl phosphates and simple diesters of phosphoric acid.

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