Diethyl Malonate → Diethyl cyclopropane-1,1-dicarboxylate

To a solution of diethyl malonate (3.2 g, 20 mmol) and anhydrous potassium carbonate powder (6.9 g, 50 mmol) in DMF (50.0 mL) was added 1,2-dibromoethane (4.136 g, 22 mmol). After stirring for 2 hrs, catalytic amount of TBAI (0.738 g, 2.0 mmol) was added and the mixture was continued to stir at room temperature for 8 hrs. The reaction mixture was filtered and the solid was washed with diethyl ether 3 times. The filtrate was diluted with water (200 mL) and extracted with diethyl ether (75 mL×4). The combined organic phases were washed with 70 mL of brine, dried over Na2SO4 and concentrated in vacuo. The residue was chromatographed with a short alumina column (1:10 (v/v) EtOAc/n-hexane) to afford the desired compound as yellow oil (3.3 g, 88.7%).

1. stirringto stir at room temperature for 8 hrs
2. filtrationThe reaction mixture was filtered
3. washthe solid was washed with diethyl ether 3 times
4. additionThe filtrate was diluted with water (200 mL)
5. extractionextracted with diethyl ether (75 mL×4)
6. washThe combined organic phases were washed with 70 mL of brine
7. dry with materialdried over Na2SO4
8. concentrationconcentrated in vacuo
9. customThe residue was chromatographed with a short alumina column (1:10 (v/v) EtOAc/n-hexane)

ORD record

ord-0980c409d1b04861bab471e4b5d8f328

Source dataset

uspto-grants-2013_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08426585B2