The invention discloses a synthesis method of 1,3-dimethyl
isocyanate cyclohexane. The method comprises the steps of pumping a metered
inert solvent into reactor capable of performing stirring and with
phosgene ingress
pipe for
bedding, performing cooling, beginning to continuously supply metered
phosgene, dropwise adding a metered
mixed solution of 1,3-hexamethylene
dimethylamine and the
inert solvent into a
reaction system to form a mixture of 1,3-hexanaphthene
dimethylamine hydrochloride and 1,3-hexanaphthene dimethylcarbamoyl
chloride (a material in the reactor is
slurry and the process isa cold photochemical reaction), after dropwise adding, heating to a
reaction temperature (the process is a heat photochemical reaction), after the reaction, removing excessive
phosgene and
hydrogen chloride through
nitrogen, and performing high vacuum rectification to form high-purity 1,3-dimethyl
isocyanate cyclohexane. The method has the advantages that raw materials are easy to obtain, the
solvent can be recycled, and the method is simple in technology, easy and simple to operate, higher in yield, mild in reaction condition and suitable for industrial production.