Phosgene → Cyclohexyl isocyanate

500 g of chlorobenzene and 2.4 g of dimethyl sulfone (0.025 mol) were placed in the glass vessel and 30 g of gaseous phosgene was introduced at room temperature. The reaction mixture was subsequently heated to 78° C., with vigorous phosgene reflux being established. While stirring vigorously at 78–80° C., a total of 99.2 g of cyclohexylamine (1 mol) dissolved in 200 g of chlorobenzene and at the same time a further 105 g of phosgene were introduced over a period of 3 hours. After addition was complete, the system was maintained at 78–80° C. for a further one hour without introduction of phosgene to allow further reaction to occur and the residual unreacted phosgene was subsequently stripped out at 50° C. by means of nitrogen. The reaction mixture obtained was a suspension from which the solid obtained was separated by filtration. 7.8 g of solid were able to be isolated in this way. The filtered crude product was worked up by distillation. Removal of the solvent and fractional distillation gave 86.8 g of cyclohexyl isocyanate (0.694 mol). This corresponds to 69.4% of the theoretical yield.

1. additionwas introduced at room temperature
2. temperaturereflux
3. additionwere introduced over a period of 3 hours
4. additionAfter addition
5. customreaction
6. customwas subsequently stripped out at 50° C. by means of nitrogen
7. customThe reaction mixture obtained
8. customobtained
9. customwas separated by filtration
10. customto be isolated in this way
11. filtrationThe filtered crude product
12. distillationwas worked up by distillation
13. customRemoval of the solvent and fractional distillation

ORD record

ord-39503a9df05e455ea0068f3f197ac811

Source dataset

uspto-grants-2006_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07064233B2