Acetone → 1,4-Diethyl 2,3-bis(1-methylethylidene)butanedioate

Temperature

60 °C

In a 1L jacketed reactor 264 mmol of acetone and 240 mmol of diethyl succinate were added to a mixture of 480 mmol of N,N-dimethylformanlide and 160 ml of toluene (solution A). In another 250 mL round bottom flask 240 mmol of potassium ethoxide were suspended in 60 mL of toluene (suspension B). The stirred suspension B was then added to solution A in 15 minutes at 60° C. The obtained mixture is stirred one hour at 60° C. Then, at 60° C, 276 mmol of ethylbromide were added dropwise in 15 minutes and the mixture stirred for six hours at 80° C. The temperature was then lowered to 60° C, 264 mmol of acetone and another batch of freshly prepared suspension B was added. The reaction mixture was stirred for 30 minutes at 60° C. After this period 276 mmol of ethylbromide were added in 15 minutes, and the obtained slurry stirred for 8 hours at 80° C. The reaction mixture was then allowed to cool to 10° C. and, after that, 120 mL of water were added. The organic layer was then separated and washed two times with 100 mL of water, the solvent evaporated to give 47 g of crude product isomers (77% of yield).

1. stirringthe mixture stirred for six hours at 80° C
2. customwas then lowered to 60° C
3. stirringThe reaction mixture was stirred for 30 minutes at 60° C
4. stirringthe obtained slurry stirred for 8 hours at 80° C
5. temperatureto cool to 10° C.
6. customThe organic layer was then separated
7. washwashed two times with 100 mL of water
8. customthe solvent evaporated
9. customto give

ORD record

ord-81a042e5a3a04962ad66e7718a2471b1

Source dataset

uspto-grants-2005_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06914153B2