Cyclohexylamine → 1H-Pyrrole, 1-cyclohexyl-2,5-dihydro-

Temperature

92 °C

A solution of 5.19 kg (52.3 moles) of cyclohexylamine in 4.0 liters of benzene was heated to mild reflux (92° C.) and then the heating discontinued. To the solution was added, dropwise, 1,635 g (13.1 moles) of 1,4-dichlorobutene at a rate sufficient to maintain gentle reflux, 3 hours time being required. Heating was continued and the reactants were heated at reflux temperature for 18 hours. The mixture was cooled to about 50° C. and filtered to remove the hydrochloride salt. Carbon dioxide was bubbled into the filtrate to precipitate excess amine carbonate salt which was removed by filtration. Solvent was removed from the filtrate by distillation under reduced pressure and the reddish fluid residue slightly contaminated with benzene weighed 1.506 g (76.2 yield).

1. additionTo the solution was added
2. temperatureHeating
3. temperaturethe reactants were heated
4. temperatureat reflux temperature for 18 hours
5. temperatureThe mixture was cooled to about 50° C.
6. filtrationfiltered
7. customto remove the hydrochloride salt
8. customCarbon dioxide was bubbled into the filtrate
9. customto precipitate excess amine carbonate salt which
10. customwas removed by filtration
11. customSolvent was removed from the filtrate by distillation under reduced pressure
12. custom1.506 g (76.2 yield)

ORD record

ord-ba0f7a92ac4b41b891e04d0e569dfd11

Source dataset

uspto-grants-1981_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04251541