Hydrochloric Acid → (2R)-1-[(tert-butoxy)carbonyl]pyrrolidine-2-carboxylic acid

HRID 1085049Notes

Reaction equation

HRID 1085049 reaction equation
C(N(CC)CC)C.[NH:8]1[CH2:15][CH2:14][CH2:13][C@@H:9]1[C:10]([OH:12])=[O:11].[C:16]1([CH3:22])[CH:21]=CC=C[CH:17]=1.Cl.[C:24]([O:27]CC)(=[O:26])C>CN(C=O)C>[CH3:17][C:16]([O:27][C:24]([N:8]1[C@@H:9]([C:10]([OH:12])=[O:11])[CH2:13][CH2:14][CH2:15]1)=[O:26])([CH3:22])[CH3:21]

Participants

7

Reactant 5

HCID 313Hydrochloric AcidHCID 1140TolueneHCID 8471TriethylamineHCID 8857Ethyl AcetateHCID 8988D-Proline

Product 1

HCID 688022(2R)-1-[(tert-butoxy)carbonyl]pyrrolidine-2-carboxylic acidYield 99%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

Triethylamine (0.2 g, 2 mmoles) was slowly added to a solution of (D-proline (0.23 g, 2 mmoles) and t-BOC-ON (0.5 g, 2 mmoles) in DMF (3 mL) at room temperature and the mixture stirred for 36 h. The DMF was coevaporated with toluene under vacuum. Aqueous hydrochloric acid (1×10-4M) (20 mL) and ethyl acetate (20 mL) were added to the flask to dissolve the residue. The organic layer was washed with water (3×20 mL) and brine (2×20 mL); dried (5 g of MgSO4) and evaporated under reduced pressure. The residue, containing the product, was chromatographed on 5 g of silica gel column (1×25 cm). Upon evaporation under reduced pressure a transparent oil was obtained. The oil was crystallized from ethyl acetate/diethyl ether to give 0.4 g (2 mmoles) (99% yield) of a crystalline powder, mp 133°-134° C. (lit.91 mp 132°-133° C.). 1H-NMR (CDCl3) δ 1.46(9Ha,s); 1.86-2.40(4Hb,m); 3.43-3.80(2Hc,m); 4.26-4.66(1Hd,m); 11.43(1He,s). IR (Nujol) 1740, 1635 cm-1.

Workup

  1. dissolutionto dissolve the residue
  2. washThe organic layer was washed with water (3×20 mL) and brine (2×20 mL)
  3. dry with materialdried (5 g of MgSO4)
  4. customevaporated under reduced pressure
  5. additionThe residue, containing the product
  6. customwas chromatographed on 5 g of silica gel column (1×25 cm)
  7. customUpon evaporation under reduced pressure a transparent oil
  8. customwas obtained
  9. customThe oil was crystallized from ethyl acetate/diethyl ether

Sources & evidence

ORD record
ord-2e1c0ffab3c54b5ca2a6636ceaa3d59a
Source dataset
uspto-grants-1991_04
Patent number
US05008245

Reaction notes

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