N-Phenyl-2-benzyloxyethylamine → [9-(2-Benzyloxy-ethyl)-2,3,4,9-tetrahydro-1H-carbazol-4-yl]-piperidin-1-yl-methanone

Temperature

50 °C

A mixture of 2-bromo-6-(piperidine-1-carbonyl)-cyclohexanone (20) (1.5 g, 5.2 mmol) and (2-benzyloxy-ethyl)-phenyl-amine (21) (3.2 g, 10.4 mmol) was stirred under N2 at 50° C. for 3 h and the reaction turned brown. The resulting mixture was dissolved in propan-2-ol (5 mL) and dry zinc chloride (2.13 g, 15.6 mmol) was added. The mixture was heated to reflux under N2 for 16 h and then concentrated in vacuo. The residue was dissolved in ethyl acetate (100 mL) and washed with 2 N HCl (30 mL), water (2×30 mL) and aqueous potassium carbonate solution (2×30 mL) then dried and concentrated in vacuo. The crude material was purified by SCX cartridge and then silica gel chromatography eluting with petrol (A) and ethyl acetate (B) (30-100% B, 12 g, 41 CV, 30 mL/min) to afford 600 mg (27%) of [9-(2-benzyloxy-ethyl)-2,3,4,9-tetrahydro-1H-carbazol-4-yl]-piperidin-1-yl-methanone (22) as an oil. The structure was confirmed by 13C NMR (75 MHz, CDCl3) δC 21.5, 21.7, 24.5, 25.7, 26.3, 273, 37.7, 42.8, 43.1, 46.7, 60.2, 68.7, 73.1, 108.2, 108.7, 117.8, 118.9, 120.5, 126.4, 127.3, 127.4, 128.1, 136.2, 137.8, 172.9.

1. temperatureThe mixture was heated
2. temperatureto reflux under N2 for 16 h
3. concentrationconcentrated in vacuo
4. dissolutionThe residue was dissolved in ethyl acetate (100 mL)
5. washwashed with 2 N HCl (30 mL), water (2×30 mL) and aqueous potassium carbonate solution (2×30 mL)
6. customthen dried
7. concentrationconcentrated in vacuo
8. customThe crude material was purified by SCX cartridge
9. washsilica gel chromatography eluting with petrol (A) and ethyl acetate (B) (30-100% B, 12 g, 41 CV, 30 mL/min)

ORD record

ord-37d7e7bd4bed4ad4a0959c406bca12a9

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08790619B2