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

HRID 1590346Notes

Reaction equation

HRID 1590346 reaction equation
CO[CH:3](O)[C:4]([O:6][CH3:7])=[O:5].[CH:9](=[O:12])[CH2:10][CH3:11]>C(NCCCC)CCC>[CH:9](/[C:10](/[CH3:11])=[CH:3]\[C:4]([O:6][CH3:7])=[O:5])=[O:12]

Participants

4

Reactant 2

HCID 527PropanalHCID 2724791Methyl 2-Hydroxy-2-methoxyacetate

Product 1

HCID 12951418(Z)-Methyl 3-methyl-4-oxobut-2-enoateYield 30.4%

Reagents, catalysts & solvents 1

HCID 8148DibutylamineCatalyst

Procedure

3.2 g (0.025 mol) of di-n-butylamine were added to a boiling, at 70° C., mixture of 120 g (1 mol) of methyl 2-methoxy-2-hydroxyacetate and 58 g (1 mol) of propionaldehyde. An exothermic reaction started immediately and the temperature rose to 100° C., when part of the reaction mixture boiled out of the flask. The temperature slowly fell to 90° C. and was maintained at this for 30 min. Fractional distillation of the reaction mixture yielded 38.9 g of methyl 3-formylcrotonate of boiling point (b.p.) 56°-68° C./10 mbar, corresponding to a yield of 30.4% of theory. The trans/cis ratio was determined by gas chromatography to be 83/17.

Workup

  1. customAn exothermic reaction
  2. customrose to 100° C.
  3. customslowly fell to 90° C.
  4. temperaturewas maintained at this for 30 min
  5. distillationFractional distillation of the reaction mixture

Sources & evidence

ORD record
ord-05be8ce8644446d78010508b58964134
Source dataset
uspto-grants-1993_04
Patent number
US05202461

Reaction notes

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