Phosgene → Cyclohexyl isocyanate

500 g of chlorobenzene and 2 g of dimethyl sulfoxide (0.025 mol) were placed in the glass vessel and 35 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 78–82° C., a total of 99.2 g of cyclohexylamine (1 mol) dissolved in 200 g of chlorobenzene and at the same time a further 113 g of phosgene were introduced over a period of 3 hours. After addition was complete, the system was maintained at 78–82° 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 40° C. by means of nitrogen. The reaction mixture obtained was a fluid suspension from which the solid obtained was separated by filtration. 2.2 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 79.7 g of cyclohexyl isocyanate (0.631 mol). This corresponds to 63.1% 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 40° 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-024be71e266c4f6c9380fb396aef771c

Source dataset

uspto-grants-2006_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07064233B2