Diethyl Malonate → Diethyl 2-vinylcyclopropane-1,1-dicarboxylate

Participants

Reaction Steps

93.4 g (583 mmol) of diethyl malonate and 1000 mL of toluene 1000 mL were added into a four-necked flask (2 L), and thereafter, 223 mL (569 mmol) of a 20% sodium ethoxide ethanol solution was added thereto as a base. The obtained mixture was stirred at room temperature for 1.5 hours, and 59.4 g of trans-1,4-dibromo-2-butene (278 mmol; a reagent manufactured by Aldrich) was then added to the reaction solution. The obtained mixture was stirred at room temperature for 2 hours, and 109 mL (278 mmol) of a 20% sodium ethoxide ethanol solution was further added to the reaction solution. The mixture was stirred at room temperature for 1 hour, and 29.1 g of trans-1,4-dibromo-2-butene (136 mmol; a reagent manufactured by Aldrich) was then added thereto. The thus obtained mixture was stirred at room temperature for 4 hours, and 347 mL of a 1 M sodium hydroxide aqueous solution was then added thereto. The mixture was stirred for 14 hours, and an organic layer was then separated. Subsequently, the organic layer was washed with 132 mL of water twice, and it was then dried over anhydrous sodium sulfate, followed by filtration. The obtained filtrate was concentrated at 40° C. under reduced pressure, so as to obtain 99.3 g of 1,1-di-ethoxycarbonyl-2-vinylcyclopropane in the form of a crude product of a light yellow oily substance. This crude product contained 83.2 g of 1,1-di-ethoxycarbonyl-2-vinylcyclopropane (yield: 94.9%). In addition, it contained no diethyl malonates.

Provenance & Evidence