反应详情

温度

240 °C

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.

1. custom500 mL 3-necked flask equipped with a reflux apparatus
2. aliquotcooler, thermometer and sampling device
3. temperaturethe temperature of the reflux
4. temperaturecooling condenser
5. customwas kept at 60° C. or more
6. customthe reverse reaction
7. customThe resulting 1,6-diisocyanatohexane (HDI) and methanol were separately collected into a flask and dry ice-acetone trap
8. customAfter the completion of the reaction
9. customthe product collected in the flask