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

HRID 1413993Notes

Reaction equation

[CH2:1](Cl)/[CH:2]=[CH:3]/[CH2:4]Cl.[C:7]([O:15][CH2:16][CH3:17])(=[O:14])[CH2:8][C:9]([O:11][CH2:12][CH3:13])=[O:10].C1C=CC=CC=1.[OH-].[K+]>O>[CH:2]([CH:3]1[CH2:4][C:8]1([C:9]([O:11][CH2:12][CH3:13])=[O:10])[C:7]([O:15][CH2:16][CH3:17])=[O:14])=[CH2:1]

Participants

Conditions

Temperature: 60 °C

Procedure

To illustrate yet another variation of the present process a reaction vessel fitted with a suitable stirrer, Dean-Stark trap, and condenser was charged with 866 g (6.9 mol) trans 1,4-dichlorobutene-2, 640 g (4.0 mol) diethyl malonate, 1.2 g (0.08 mol percent based on malonate) tricaprylylmethylammonium chloride and 1.8 liters benzene. The reactor and its contents were heated to 60° C. with stirring and incremental additions of flaked solid (85%) potassium hydroxide made over a 4.75-hour period while azeotropically removing water of reaction. A total of 528 grams solid KOH were charged. After 5.5 hours the theoretical amount of water was removed and the reaction mixture was cooled, filtered to remove potassium salts and the benzene solution concentrated. The crude brown oil, upon distillation at reduced pressure, yielded the desired diethyl 2-vinylcyclopropane-1,1-dicarboxylate (65.7% yield).

Workup

customfitted with a suitable stirrer
customAfter 5.5 hours the theoretical amount of water was removed
temperaturethe reaction mixture was cooled
filtrationfiltered
customto remove potassium salts
concentrationthe benzene solution concentrated
distillationThe crude brown oil, upon distillation at reduced pressure

Sources & evidence

ORD record: ord-a5ae8e486ab24734ac473fd094c8d0df
Source dataset: uspto-grants-1981_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04252739

Reaction notes

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