HCID 67646660, compound → HCID 86751149, compound

HRID 965265Notes

Reaction equation

HRID 965265 reaction equation
[C:1]([CH2:8][CH2:9][CH:10]([NH2:31])[C:11]([O:22][C:23](=[O:30])[C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1)([C:17]([O:19][CH2:20]C)=[O:18])[C:12]([O:14][CH2:15]C)=[O:13])([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2]>CO>[C:23]([O:22][CH3:11])(=[O:30])[C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1.[C:1]([CH2:8][CH2:9][CH:10]([NH2:31])[C:11]([OH:22])([C:12]([O:14][CH3:15])=[O:13])[C:17]([O:19][CH3:20])=[O:18])([O:3][C:4]([CH3:6])([CH3:5])[CH3:7])=[O:2]

Participants

4

Reactant 1

HCID 67646660HCID 67646660, compound

Product 2

HCID 7150Methyl BenzoateHCID 86751149HCID 86751149, compoundYield 129%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of 4 g of ethyl 5-BOC-amino-2-benzoyloxy-2-ethoxycarbonyl-pentanoate and 2 g of K2 CO3 in 40 ml of anhydrous methanol, cooled to 0°-5° C., is stirred for 1 h. After filtration of the potassium carbonate excess, the solution is acidified to pH 6 with 2N HCl and filtered from the salts which separate. Solvent is evaporated off under vacuum and the residue is partitioned between cold water and ethyl acetate. The organic phase is washed repeatedly with a 5% K2CO3 cold solution and with water to neutrality, dried over sodium sulfate and evaporated to dryness. The residue (3 g) is eluted, purified on 30 g of silica gel, eluent hexane-ethyl acetate from 95:5 to 80:20, to give methyl benzoate and 1.8 g of methyl 5-BOC-amino-2-hydroxy-2-methoxycarbonyl-pentanoate (oil). TLC (4:6 AcOEt-hexane) Rf=0.19 I.R.: (--OH and --NH--3400 cm-1 broad peak) (C=O 1730 cm-1 broad peak) NMR (CDCl3 /TMS): (δ) 1.45 s; 1.45-1.6 m; 2.0-2.1 m; 3.05-3.2 q; 3.8 s; 4.6 s. By acidification of the basic extracts with 20% KHSO4 and subsequent extraction with ethyl acetate, 0.17 g of 5-BOC-amino-2-hydroxy-2-methoxycarbonyl-pentanoic acid are obtained (oil) TLC (3:1:1 nBuOH-AcOH-H2O) Rf=0.54

Workup

  1. temperaturecooled to 0°-5° C.
  2. filtrationAfter filtration of the potassium carbonate excess
  3. filtrationfiltered from the salts which
  4. customseparate
  5. customSolvent is evaporated off under vacuum
  6. customthe residue is partitioned between cold water and ethyl acetate
  7. washThe organic phase is washed repeatedly with a 5% K2CO3 cold solution and with water to neutrality
  8. dry with materialdried over sodium sulfate
  9. customevaporated to dryness
  10. washThe residue (3 g) is eluted
  11. custompurified on 30 g of silica gel, eluent hexane-ethyl acetate from 95:5 to 80:20

Sources & evidence

ORD record
ord-124ee932e23542b3bb26c51ebc781041
Source dataset
uspto-grants-1998_06
Patent number
US05773465

Reaction notes

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