Triethylamine → 1-Carbobenzoxy-4-piperidinecarboxylic Acid

Temperature

5 °C

Benzyl chloroformate (8.5 g) was added dropwise to a stirred mixture of ethyl piperidine-4-carboxylate (7.85 g), triethylamine (6.95 ml) and methylene chloride (50 ml) which had been cooled to 5° C. The mixture was stirred at ambient temperature for 18 hours. The mixture was partitioned between ethyl acetate and 2N aqueous hydrochloric acid. The organic phase was washed with water and with brine, dried (MgSO4) and evaporated. The residue was dissolved in methanol (100 ml) and 2N aqueous sodium hydroxide (125 ml) was added. The mixture was stirred at ambient temperature for 1 hour. The mixture was concentrated by evaporation and the residue was partitioned between diethyl ether and water. The aqueous phase was acidified to pH3 by the addition of concentrated hydrochloric acid and the mixture was extracted with ethyl acetate. The organic extract was washed with water, dried (MgSO4) and evaporated to give 1-benzyloxycarbonylpiperidine-4-carboxylic acid (10.1 g).

1. customThe mixture was partitioned between ethyl acetate and 2N aqueous hydrochloric acid
2. washThe organic phase was washed with water and with brine
3. dry with materialdried (MgSO4)
4. customevaporated
5. dissolutionThe residue was dissolved in methanol (100 ml)
6. addition2N aqueous sodium hydroxide (125 ml) was added
7. stirringThe mixture was stirred at ambient temperature for 1 hour
8. concentrationThe mixture was concentrated by evaporation
9. customthe residue was partitioned between diethyl ether and water
10. additionThe aqueous phase was acidified to pH3 by the addition of concentrated hydrochloric acid
11. extractionthe mixture was extracted with ethyl acetate
12. extractionThe organic extract
13. washwas washed with water
14. dry with materialdried (MgSO4)
15. customevaporated

ORD record

ord-b9ba83660a124eb7b8a3baebd44859e9

Source dataset

uspto-grants-2001_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06225309B1