methyl N-[6-(methoxycarbonylamino)hexyl]carbamate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a reinforced glass reactor with a capacity of 5 ml 2 ml of dimethyl carbonate and 150 mg of 1,6-dinitrohexane and 100 mg of Au/CeO2 (1 wt % gold relative to cerium) are introduced. The reactor is closed and purged with N2 to remove oxygen from the solution. Then the reactor is charged at 15 bars of hydrogen and immersed in a silicone bath preheated at 90° C. The suspension is magnetically stirred for 8 hrs. After this time, the reactor is discharged at atmospheric pressure, opened and the mixture is filtered. A gas chromatography analysis revealed the presence of 1,6-bis (methoxycarbonylamino) hexane in an 85% yield. The reactor is closed purged with N2 to remove oxygen from the solution Then the reactor is charged at 15 bars of hydrogen immersed in a silicone bath preheated at 90° C the mixture is filtered

Conditions: temp:240.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 500 mL 3-necked flask equipped with a reflux apparatus, cooler, thermometer and sampling device was charged with 1,6-bis(methoxycarbonylamino)hexane (HDC, 50 g), benzyltoluene (250 g), di-n-butyltin dilaurate (0.05 g), and 1-methylimidazolium-3-propanesulfonate (0.1 g) as a zwitterionic compound, which were heated to 240° C. under 20 mmHg pressure. The reaction time was 2 hours, and the temperature of the reflux and cooling condenser was kept at 60° C. or more to prevent the reverse reaction. The resulting 1,6-diisocyanatohexane (HDI) and methanol were separately collected into a flask and dry ice-acetone trap. After the completion of the reaction, the product collected in the flask was analyzed with gas chromatography, which showed 94.1% yield of HDI, 5.2% yield of 1-isocyanato-6-methoxycarbonylaminohexane (HMI), and only 1.3 g of high-boiling polymer precipitates. 500 mL 3-necked flask equipped with a reflux apparatus cooler, thermometer and sampling device the temperature of the reflux cooling condenser was kept at 60° C. or more the reverse reaction The resulting 1,6-diisocyanatohexane (HDI) and methanol were separately collected into a flask and dry ice-acetone trap After the completion of the reaction the product collected in the flask