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. Heat was reapplied 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. Carbon dioxide was bubbled into the filtrate to precipitate excess amine carbonate 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% yield).

1. additionTo the solution was added
2. temperatureHeat
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
8. customCarbon dioxide was bubbled into the filtrate
9. customto precipitate excess amine carbonate which
10. customwas removed by filtration
11. customSolvent was removed from the filtrate by distillation under reduced pressure

ORD record

ord-b377109ab96d469c846532b1cff41539

Source dataset

uspto-grants-1981_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04254135