From Cyano-compounds and Phosphorus v Halides

From Cyano-compounds and Phosphorus(v) Halides.—Continued reports of the reactions of alkyl cyanides with phosphorus pentachloride appear. With dicyanides the formation of phosphazenes occurs via a series of intermediates whose stability varies with the nature of X  

The second cyano-group reacts with PCI5 at 150—160 °C  

Analogous reactions with tricyanides have also been reported 

The latter products readily add chlorine at the olefinic linkage and are hydrolysed by aqueous sodium hydroxide to give (5) in good yield. 

With 3-aminopropionitrile hydrochloride, phosphorus pentachloride produces phosphazene linkages at both ends of the alkyl chain, as might be expected from the foregoing discussion  

From Cyano-compounds and Phosphorus(v) Halides.—The products from the reactions of acetonitrile and chloroacetonitriles with phosphorus pentachloride have been re-examined. The formation of compounds of structure (4) from the reaction with acetonitriles is confirmed, as well as the intermediates (5), but there was no evidence for the existence of cis-and trans-isomers of (4) or (5) (X = H) as previously postulated. The 

However, nitriles of the type RCH2CN (R = alkyl or aryl) give resinous products with phenyltetrachlorophosphorane, possibly because the 

These compounds were converted to imino-derivatives on reaction with arenesulphonamides  

Malononitriles undergo interesting reactions with phosphorus penta-chloride. For example (8) is cyclized to a monophosphazene (9) in refluxing chlorobenzene solution and may be re-formed by addition of 

The aryl tricyanides ArHC(CN)CH(CN)2 undergo a cyclization reaction with phosphorus pentachloride to give the azoles (11). This contrasts 

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