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

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence