Cyclohexylamine → 1-Cyclohexylpyrrolidin-3-ol

Temperature

130 °C

With stirring 1,4-dibromo-2-butanol (696 g, 3 mol) was added dropwise to cyclohexylamine (595 g, 6 mol). The addition was rapid until the reaction temperature reached 130° C. and then slowed so as to maintain the temperature at 130°-135° C. When the addition was completed the mixture was heated at 130° C. for 2 h. The mixture was then poured into 3 L of water with stirring. The aqueous mixture was filtered and the filtrate extracted with 1 L of ether. The aqueous solution was basified with 50% sodium hydroxide solution. The oil which separated from solution was removed. The aqueous layer was extracted with three 400 ml portions of ether and the extract combined with the oil. The ether solution was dried (Na2SO4) and concentrated. The residual oil was distilled and the fraction boiling at 165°-180° C./39 mm was collected. A higher boiling fraction (180°-190° C./39 mm) was collected and redistilled to give some additional material boiling at 165°-180° C./39 mm for a total yield of 329.6 g (77%).

1. additionThe addition
2. customreached 130° C.
3. temperatureto maintain the temperature at 130°-135° C
4. additionWhen the addition
5. filtrationThe aqueous mixture was filtered
6. extractionthe filtrate extracted with 1 L of ether
7. customThe oil which separated from solution
8. customwas removed
9. extractionThe aqueous layer was extracted with three 400 ml portions of ether
10. dry with materialThe ether solution was dried (Na2SO4)
11. concentrationconcentrated
12. distillationThe residual oil was distilled
13. customthe fraction boiling at 165°-180° C./39 mm was collected
14. customA higher boiling fraction (180°-190° C./39 mm) was collected
15. distillationredistilled

ORD record

ord-534159c7e3a14039ab13373ce04fb0db

Source dataset

uspto-grants-1992_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05109013