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Abstract

An aromatic urethane is obtained at high yield without involving corrosion of a stainless steel reactor by interacting an aromatic nitro compound, an organic compound having at least one hydroxyl group therein and carbon monoxide in the presence of a catalyst composed of (1) palladium, ruthenium, rhodium or compounds thereof, (2) a Lewis acid, and (3) a tertiary amine. For instance, 2,4-dinitrotoluene, ethanol and carbon monoxide placed in a SUS-32 reactor are interacted in the presence of a catalyst composed of (1) 5% palladium on carbon, (2) ferric chloride, and (3) pyridine to obtain 2,4-diethyldicarbamatetoluene without corrosion of the reactor. After completion of the reaction, the catalyst and reaction product are separated from the reaction system; e.g., the insoluble catalyst is first separated and then the reaction solution is cooled down, e.g., to room temperature, to separate the reaction product as crystals, followed by separation of the crystals by filtration. Then, the reaction may be repeated by adding fresh 2,4-dinitrotoluene and ethanol and the separated catalyst to the resultant fitrate under pressurized conditions of a carbon monoxide atmosphere. By repeating the reaction in this manner, 2,4-diethyldicarbamatetoluene with a purity of 98% can be obtained at a yield of 90%.

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First Claim