Propanal → (Z)-Methyl 3-methyl-4-oxobut-2-enoate

HRID 1590350Notes

Reaction equation

HRID 1590350 reaction equation
[CH:1](=[O:4])[CH2:2][CH3:3].[C:5]([O:9][CH3:10])(=[O:8])[CH:6]=O.CO.C(OC(=O)C)(=O)C>N(CC(O)=O)C>[CH:1](/[C:2](/[CH3:3])=[CH:6]\[C:5]([O:9][CH3:10])=[O:8])=[O:4]

Participants

6

Reactant 4

HCID 527PropanalHCID 887MethanolHCID 7918Acetic AnhydrideHCID 70205Acetic acid, 2-oxo-, methyl ester

Product 1

HCID 12951418(Z)-Methyl 3-methyl-4-oxobut-2-enoateYield 84.5%

Reagents, catalysts & solvents 1

HCID 1088SarcosineCatalyst

Conditions

Temperature
80 °C

Procedure

688 g (11.9 mol) of propionaldehyde were added within 45 min to a mixture of 968 g (11 mol) of methyl glyoxylate, 352 g (11 mol) of methanol and 9.6 g (0.11 mol) of sarcosine at 50° C. After the addition was complete, the mixture was stirred at 80° C. for 1 h and then 2805 g (27.5 mol) of acetic anhydride were added. Distillation was carried out under atmospheric pressure with a column until the top temperature was 105° C., to remove some of the methyl acetate/acetic acid, and then up to 125° C. to remove a mixture of methyl acetate, acetic acid, acetic anhydride and methyl 3-formylcrotonate. Distillation was then continued under 250 mbar up to 105° C. and then under 30 mbar until the top temperature was 90° C. The combined distillates were redistilled to give 1184 g (9.3 mol) of methyl 3 -formylcrotonate, corresponding to a yield of 84% of theory.

Workup

  1. additionAfter the addition
  2. distillationDistillation
  3. customwas 105° C.
  4. customto remove some of the methyl acetate/acetic acid
  5. customup to 125° C. to remove
  6. additiona mixture of methyl acetate, acetic acid, acetic anhydride and methyl 3-formylcrotonate
  7. distillationDistillation
  8. customwas 90° C
  9. distillationThe combined distillates were redistilled

Sources & evidence

ORD record
ord-d8ec9a13f04a467bb17b6fa932aa57c8
Source dataset
uspto-grants-1993_04
Patent number
US05202461

Reaction notes

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