Citric Acid → (3S,5R)-1-(tert-butoxycarbonyl)-5-(methoxycarbonyl)piperidine-3-carboxylic acid (1R)-1-phenylethylamine salt

HRID 1475178Notes

Reaction equation

HRID 1475178 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[CH:5][C:6]2N=CC=[C:9]([C@H:13](O)[C@@H]3N4C[C@H](C=C)C(CC4)C3)[C:7]=2[CH:8]=1.[O:25]=[C:26]1[O:33][C:32](=[O:34])[CH:31]2[CH2:35][CH:27]1[CH2:28][N:29]([C:36]([O:38][C:39]([CH3:42])([CH3:41])[CH3:40])=[O:37])[CH2:30]2.CO.C(O)(=O)CC(CC(O)=O)(C(O)=O)O>C(OCC)(=O)C.O1CCCC1>[C:7]1([C@H:9]([NH2:29])[CH3:13])[CH:6]=[CH:5][CH:4]=[CH:3][CH:8]=1.[C:39]([O:38][C:36]([N:29]1[CH2:30][C@H:31]([C:32]([O:2][CH3:1])=[O:34])[CH2:35][C@H:27]([C:26]([OH:33])=[O:25])[CH2:28]1)=[O:37])([CH3:42])([CH3:41])[CH3:40]

Participants

7

Reactant 4

HCID 311Citric AcidHCID 887MethanolHCID 5953(S)-[(2R,5R)-5-ethenyl-1-azabicyclo[2.2.2]octan-2-yl]-(6-methoxyquinolin-4-yl)methanolHCID 59778297Tert-butyl 2,4-dioxo-3-oxa-7-azabicyclo[3.3.1]nonane-7-carboxylate

Product 1

HCID 86680826(3S,5R)-1-(tert-butoxycarbonyl)-5-(methoxycarbonyl)piperidine-3-carboxylic acid (1R)-1-phenylethylamine saltYield 139.1%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
0 °C

Procedure

Under a nitrogen stream, quinidine (69.9 g, 0.215 mol) and tetrahydrofuran (200 mL) were charged and the mixture was cooled to −5 to 5° C. tert-Butyl 2,4-dioxo-3-oxa-7-azabicyclo[3,3,1]nonane-7-carboxylate (50.0 g, 0.196 mol) was added at the same temperature, and the used container was washed with tetrahydrofuran (50.0 mL). Methanol (9.41 g, 0.29 4 mol) was added dropwise at −5 to 5° C., and the mixture was stirred at −5 to 5° C. for 2 hr. To the reaction mixture were added ethyl acetate (350 mL) and 20 w/v % aqueous citric acid solution (250 mL), and the mixture was partitioned. The aqueous layer was extracted again with ethyl acetate (125 mL×2). The organic layers were combined and washed successively with 20 w/v % aqueous citric acid solution (250 mL) and water (250 mL×2). The organic layer was concentrated under reduced pressure. To the residue were added ethanol (100 mL) and ethyl acetate (450 mL), the mixture was heated to 60-70° C., and (R)-phenethylamine (23.7 g, 0.196 mol) was added. The mixture was stirred at 50-60° C. for 1 hr, at 20-30° C. for 1 hr and at −5 to 5° C. for 1 hr. The precipitated crystals were collected by filtration, washed with ethanol-ethyl acetate (2:9, 100 mL), and dried under reduced pressure at 50° C. to give (3S,5R)-1-(tert-butoxycarbonyl)-5-(methoxycarbonyl)piperidine-3-carboxylic acid (1R)-1-phenylethylamine salt as a white crystalline powder (55.7 g, yield 69.6%).

Workup

  1. additionwas added at the same temperature
  2. washthe used container was washed with tetrahydrofuran (50.0 mL)
  3. customthe mixture was partitioned
  4. extractionThe aqueous layer was extracted again with ethyl acetate (125 mL×2)
  5. washwashed successively with 20 w/v % aqueous citric acid solution (250 mL) and water (250 mL×2)
  6. concentrationThe organic layer was concentrated under reduced pressure
  7. additionTo the residue were added ethanol (100 mL) and ethyl acetate (450 mL)
  8. temperaturethe mixture was heated to 60-70° C.
  9. stirringThe mixture was stirred at 50-60° C. for 1 hr, at 20-30° C. for 1 hr and at −5 to 5° C. for 1 hr
  10. filtrationThe precipitated crystals were collected by filtration
  11. washwashed with ethanol-ethyl acetate (2:9, 100 mL)
  12. customdried under reduced pressure at 50° C.

Sources & evidence

ORD record
ord-7b11a1c7f0844f8d99589378eb88fa06
Source dataset
uspto-grants-2015_04
Patent number
US09018374B2

Reaction notes

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