Methanol → 1,1-Cyclopropanedicarboxylic acid

Participants

Reaction Steps

In a 4 liter multinecked flask, 800 ml of aqueous saturated K2 SO4 solution (from previous batches, neutralized), 500 ml of methanol and 330 g of KOH (85%, 5.0 mol) are heated and then, at 68° C., over a period of 90 minutes, a 316.2 g amount of dimethyl cyclopropane-1,1-dicarboxylate (2.0 mol) is added gradually. During the postreaction time of 4 hours, some of the methanol distills. After the reaction solution has cooled it is acidified, with cooling, with a 281 g amount of sulfuric acid (96% strength, 2.75 mol) which has previously been diluted with 100 ml of water. The K2SO4 which crystallizes is filtered via a sintered disk, washed with methanol and dried: 380 g (87.2% of the theoretical yield).

Provenance & Evidence