Silicon tetraisocyanate reaction with

Silicon tetraisocyanate, reaction with cyclohexylamiae to yield cyclo-hexylurea, 46, 69... 

Reaction of amines with silicon tetraisocyanate and silicon tetraiso-thiocyanate to give ureas and thioureas, respectively [101a, b]. 

When freshly prepared lead cyanate (642 g. 2.2 mols 10% theoretical excess) is employed in the above procedure instead of silver isocyanate, the reaction is only slightly exothermic. The silicon(IV) chloride can therefore be added at a fairly rapid rate after the reaction has been initiated by heating to 35 to 40". The mixture is then refluxed with vigorous stirring for 3 hours. After the benzene is distilled, the 3ueld of silicon tetraisocyanate is 121 g. [61.8% based on silicon(IV) chloride]. 

Phenylsilicon triisocyanate added dropwise to a well-stirred mixture of 3 moles allylamine in anhydrous benzene, and heated 2 hrs. on a steam bath after the exothermic reaction has moderated allylurea. Y 98%. F. e., also with silicon tetraisocyanate and other silicon isocyanates, s. R. G. Neville, J. Org. Ghem. 23, 937 (1958). 

---