4-(2,6-Dichlorophenyl)-2,6-piperidinedione → 4-(2,6-dichloro-phenyl)-piperidine hydrochloride

Temperature

0 °C

9.0 g (34.9 mmol) of 4-(2,6-dichloro-phenyl)-piperidine-2,6-dione were dissolved in 150 mL of dry THF under a nitrogen atmosphere. The resulting solution was cooled to 0° C. and 35 mL (ca 350 mmol) of borane-methylsulphide complex dissolved in 100 mL of dry THF were added dropwise. The reaction mixture was allowed to warm to room temperature, heated to reflux for 3 h, then cooled to −5° C. and quenched by careful addition of 150 mL of 10% HCl solution. The reaction mixture was subsequently heated to reflux for 3 h, then, after cooling, the volatiles were removed in vacuo. The residue was taken up in water, basified with 2 N NaOH solution and extracted with AcOEt The organic phase was dried and the solvent was removed in vacuo. The resulting oil was taken up in CH2Cl2, brought to acidic pH with Et2O/HCl and the solvent was removed in vacuo. The resulting solid was triturated with Et2O, filtered and dried, yielding 7.1 g of the title compound.

1. additionwere added dropwise
2. temperatureto warm to room temperature
3. temperatureheated
4. temperatureto reflux for 3 h
5. temperaturecooled to −5° C.
6. customquenched by careful addition of 150 mL of 10% HCl solution
7. temperatureThe reaction mixture was subsequently heated
8. temperatureto reflux for 3 h
9. temperatureafter cooling
10. customthe volatiles were removed in vacuo
11. extractionextracted with AcOEt The organic phase
12. customwas dried
13. customthe solvent was removed in vacuo
14. customthe solvent was removed in vacuo
15. customThe resulting solid was triturated with Et2O
16. filtrationfiltered
17. customdried

ORD record

ord-08c270fa58a04cd2a002242880131e0a

Source dataset

uspto-grants-2006_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07115633B2