Phosphorylation of formamide

Summary

• 1. Mixed amides of formic and dialkyl hydrogen phosphites (dialkyl formylphosphoramidites) (alkyl=C₂H₅; i-C₃H₇; i-C₄H₉) were synthesized by the reaction of formamide or N-ethylformamide with dialkyl phosphorochloridites.

• 2. The formation of unsubstituted dialkyl formylphosphoramidites in this reaction passes through the stage of the formation of a pyrophosphorous ester and its reaction with formamide.

• 3. In the reaction of diethyl phosphorochloridate with formamide or substituted formamide the latter is dehydrated, and as a result of subsequent reactions tetraethyl pyrophosphate is formed. Diisopropyl phosphorochloridite reacts with formanilide analogously, and the final reaction product is the pyrophosphorous ester.

• 4. The reactions of some dialkyl ethylformylphosphoramidites with sulfur, nitrogen dioxide, and chloral were investigated. As a result of these reactions, the following compounds were obtained: O,O-dialkyl ethylformylphosphoramidothioates (alkyl=i-C₃H₇; i-C₃H₉), diisobutyl ethylformylphosphoramidate, and alkyl 2, 2-dichlorovinyl ethylformylphosphoramidates (alkyl=C₂H₅; i-C₃H₇; C₄H₉).