Preparation of dialkyl (N-cyanoimido)carbonates from dialkyl imidocarbonates and cyanogen halides
AssigneeCiba-Geigy Corporation
InventorsMichael A. Oliver, Ward H. Oliver
Life of this patent
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Abstract
Dialkyl (N-cyanoimido) carbonates are prepared in good yield in a non-aqueous solvent by a process which comprises either (a) adding a cyanogen halide at a controlled rate to a reactor containing an unsubstituted or substituted dialkyl imidocarbonate, an inorganic base and/or a trialkyl amine, or (b) by adding a trialkyl amine to a solution of the unsubstituted or substituted dialkyl imidocarbonate and a cyanogen halide. The dialkyl imidocarbonate precursors are prepared by using a stoichiometric ratio (2:1) of alcohol to cyanogen halide in the presence of an acid acceptor and in a non-aqueous solvent. Dialkyl (N-cyanoimido)carbonates are useful as intermediates for pesticides and pharmaceuticals.
Claims18
A process for the preparation of an unsubstituted or substituted dialkyl (N-cyanoimido)carbonate which comprises reacting a cyanogen halide with an unsubstituted or substituted dialkyl imidocarbonate in the presence of a trialkyl amine or a catalytic amount of a trialkyl amine and an inorganic base.
A process according to clam 5 wherein 1 to 10 mole % of a trialkyl amine is used in addition to an alkali metal carbonate.
Dependencies are inferred from the claim text.