Methanol, magnesium salt (2:1) → HCID 19705548, compound

HRID 727544Notes

Reaction equation

HRID 727544 reaction equation
C(OC([N:8]1[CH2:12][CH2:11][C:10]([CH2:24][CH:25]([CH3:27])[CH3:26])([CH:13]([C:21]([CH3:23])=[CH2:22])[C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[C:9]1=[O:28])=O)(C)(C)C.C[O-].[Mg+2].C[O-]>CO>[CH3:26][CH:25]([CH3:27])[CH2:24][C:10]1([CH:13]([C:21]([CH3:23])=[CH2:22])[C:14]([O:16][C:17]([CH3:19])([CH3:18])[CH3:20])=[O:15])[CH2:11][CH2:12][NH:8][C:9]1=[O:28]

Participants

4

Reactant 2

HCID 164537Methanol, magnesium salt (2:1)HCID 19705440HCID 19705440, compound

Product 1

HCID 19705548HCID 19705548, compoundYield 117.4%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of tert-butyl N-tert-butyloxycarbonyl-3-(2-methylpropyl)-2-oxo-α-(propen-2-yl)-3-pyrrolidineacetate (5.40 g, 13.7 mmol) in MeOH (70 mL) is treated with magnesium methoxide (74.7 mL, 68.5 mmol, 10.3 wt % in MeOH). The resultant solution is stirred under N2 at room temperature for 16 hours. The solution is quenched with 1:1 glacial AcOH/H2O (100 mL). The solution is reduced to a minimal volume under reduced pressure, and the unprotected lactam is extracted into CH2Cl2 (3×100 mL). The organic layers are combined, washed with saturated NH4Cl (100 mL), brine (100 mL), dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure to give 4.75 g of a gold oil. The oil is purified by silica gel chromatography (100 g SG, 25% EtOAc/hexane) to yield 3.85 g (96%) of the title compound as an off-white, low-melting solid.

Workup

  1. customThe solution is quenched with 1:1 glacial AcOH/H2O (100 mL)
  2. extractionthe unprotected lactam is extracted into CH2Cl2 (3×100 mL)
  3. washwashed with saturated NH4Cl (100 mL), brine (100 mL)
  4. dry with materialdried over anhydrous Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-c9ca78ff4ea64cc8afa7e3196c9dca27
Source dataset
uspto-grants-1998_01
Patent number
US05712300

Reaction notes

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