By Miscellaneous Other Methods

The insertion reaction of heterocumulenes can be used to syuthesize carbodiimides having two different substituents. For example, the carbamate 157 derived from an isocyanate and bis(tributyltin)oxide can be reacted with an isothiocyanate to give a carbodiimide 158 with substituents derived from the isocyanate and the isothiocyanate.  

The photolysis of sulfihmine 159 affords N-phenyl-N -2,6-dimethylphenylcarbodiimide 160 in 26% yield. N-phenyl-N -2,6-diethylphenyl- (18%) and N-phenyl-2,6-dichlorophenyl-carbodiimide (34 %) are similarly obtained.  

The photolysis of boryl substituted nitrilimines also affords the corresponding carbo -diimides.  

Reaction of 3-chlorobenzothiazole-S-dioxide 161 with phenylurea in the presence of lithium carbonate affords an 85 % yield of the shown carbodiimide 162.  

The reaction product derived from isonitriles and primary amines in the presence of Pd(II)Cl2 reacts with silver oxide to give carbodiimides 163.  

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Synthesis by Miscellaneous Other Methods. An 5 2 reaction with inversion at the cyclpropyl carbon in (103) has been demonstrated unambiguously. 

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