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

35.2 g (220 mmol) of malonic acid diethyl esterdiethyl malonate and 400 mL of toluene were added into a three-necked flask (1 L), and thereafter, 82.3 mL (210 mmol) of a 20% sodium ethoxide ethanol solution was added thereto as a base. The obtained mixture was stirred at room temperature for 0.5 hours, and 12.5 g of trans-1,4-dichloro-2-butene (100 mmol; a reagent manufactured by Tokyo Chemical Industry Co., Ltd.) was then added to the reaction solution. The obtained mixture was stirred at room temperature for 5 days, and 240 mL of a 1 M sodium hydroxide aqueous solution was then added to the reaction solution. The mixture was stirred for 1 hour, and an organic layer was then separated. A water layer was re-extracted with 200 mL of toluene, and organic layers were then gathered. The gathered organic layer was washed with 200 mL of water three times, and the resultant was then filtrated, while washing the residue with toluene. The obtained filtrate was concentrated at 45° C. under reduced pressure, so as to obtain 24.4 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 19.5 g of 1,1-di-ethoxycarbonyl-2-vinylcyclopropane (yield: 92%).

1. addition) was then added to the reaction solution
2. stirringThe obtained mixture was stirred at room temperature for 5 days
3. stirringThe mixture was stirred for 1 hour
4. customan organic layer was then separated
5. extractionA water layer was re-extracted with 200 mL of toluene, and organic layers
6. washThe gathered organic layer was washed with 200 mL of water three times
7. filtrationthe resultant was then filtrated
8. washwhile washing the residue with toluene
9. concentrationThe obtained filtrate was concentrated at 45° C. under reduced pressure

ORD record

ord-62f1982c7e9143d3ba340f07f29add1e

Source dataset

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09061991B2