| 摘要 |
A silicon isocyanate or isothiocyanate, or a phosphorus isocyanate or isothiocyanate, is produced together with lithium chloride by reacting silicon tetrachloride or phosphorus trichloride with lithium isocyanate or isothiocyanate. Depending on the amount of lithium isocyanate or isothiocyanate employed one or more chlorine atoms of the silicon tetrachloride or phosphorus trichloride are replaced by an isocyanate or isothiocyanate group. The silicon or phosphorus chloride may be added to a suspension of lithium isocyanate or isothiocyanate in an inert organic liquid which is a solvent for the isocyanate product but not for the lithium chloride also produced and heating the mixture under reflux. Solvents specified are benzene, toluene, xylene, mesitylene, ethylbenzene, n-propylbenzene, cumene, naphthalene and tetrahydronaphthalene. The lithium chloride product may be converted into lithium carbonate by reaction with sodium carbonate, and the lithium carbonate may be converted into lithium isocyanate or isothiocyanate for recycling to the process by heating with urea or thiourea. Three examples are given.
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