Carbon Dioxide → 1,1-Dimethyl 2-methylcyclopropane-1,1-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

The apparatus described in Example 1 was charged successively with 132.1 g dimethyl malonate (1.0 mol), 166 g (1.2 mols) finely comminuted potassium carbonate, 339 g 1,2-dichloropropane (3.0 mols) and 250 ml of dimethylformamide. While stirring vigorously, the reaction mixture was heated to 118° C., and the reaction temperature was increased to 125° C. over a period of 15 hours. While releasing carbon dioxide, the reaction mixture distilled off as an azeotrope which was separated into dichloropropane and water in the phase separator and was then drained. Flash distillation was used to separate the salts and high boiling components, and the distillate was separated by way of a column into the fractions 1,2-dichloropropane, dimethylformamide and 1,1-dicarbomethoxy-2-methylcyclopropane. The target product distilled over at 78° C./14 mbar and was identified by means of H-NMR as the desired target product.

Provenance & Evidence