2-Oxobutanoic Acid → HCID 23404558, compound

HRID 1351753Notes

Reaction equation

HRID 1351753 reaction equation
O=[C:2]([CH2:6][CH3:7])[C:3]([OH:5])=[O:4].C1(C)C=CC=CC=1.[NH:15]1[CH2:19][CH2:18][CH2:17][C:16]1=[O:20]>O>[O:20]=[C:16]1[CH2:17][CH2:18][CH2:19][N:15]1/[C:2](=[CH:6]\[CH3:7])/[C:3]([OH:5])=[O:4]

Participants

5

Reactant 3

HCID 582-Oxobutanoic AcidHCID 1140TolueneHCID 120252-Pyrrolidone

Product 1

HCID 23404558HCID 23404558, compoundYield 70%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A1 l flask fitted with a magnetic stirring bar and a Dean-Stark trap was charged with 2-oxobutanoic acid (25 g, 245 mmol), toluene (500 ml, 20 vol) and 2-pyrrolidinone (37.2 ml, 490 mmol, 2 equiv). The reaction mixture was stirred under reflux with azeotropic removal of water via the Dean-Stark trap for 5.5 hours. The solution was then concentrated to ca. 90 ml (3.6 vol) and allowed to cool slowly to ambient temperature. Off-white solid started to come out of solution at around 55° C. The solid was filtered, the cake was washed with toluene (2×1 vol) followed by dichloromethane (3×1 vol) and dried on the filter under vacuum for 5 min to afford crude material (28 g, 70% yield). The crude product was dissolved in acetone (450 ml, 16 vol) at reflux, cooled slowly to ambient temperature and allowed to crystallise over 12 hrs at −15 to −20° C. Pure product was obtained as a white crystalline solid (21 g, 51% overall yield).

Workup

  1. concentrationThe solution was then concentrated to ca. 90 ml (3.6 vol)
  2. customto come out of solution at around 55° C
  3. filtrationThe solid was filtered
  4. washthe cake was washed with toluene (2×1 vol)
  5. customdried on the
  6. filtrationfilter under vacuum for 5 min

Sources & evidence

ORD record
ord-28a3e93061e846699218f5cb648b94d7
Source dataset
uspto-grants-2007_05
Patent number
US07217826B2

Reaction notes

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