Malononitrile → Methyl 3,3-dicyano-2,2-dimethylpropanoate

In THF (91 ml), 3 g (45.411 mmol) of malononitrile were added slowly to 1.816 g (45.411 mmol) of sodium hydride (60% in mineral oil). Subsequently, 5.876 ml (45.411 mmol) of methyl 2-bromo-2-methylpropanoate were added and the mixture was stirred at RT overnight. Thereafter, another 5.876 ml (45.411 mmol) of methyl 2-bromo-2-methylpropanoate were added and the mixture was heated at 50° C. overnight. Then yet another 1.762 ml (13.623 mmol) of methyl 2-bromo-2-methylpropanoate were added and the mixture was heated at 50° C. for a further 4 h. Saturated aqueous sodium bicarbonate solution was then added to the reaction, and the mixture was extracted three times with ethyl acetate. The combined organic phases were washed with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered and concentrated to dryness. This gave 8.9 g of crude product, which was purified by chromatography on silica gel (cyclohexane-ethyl acetate 4:1).

1. temperaturethe mixture was heated at 50° C. overnight
2. temperaturethe mixture was heated at 50° C. for a further 4 h
3. extractionthe mixture was extracted three times with ethyl acetate
4. washThe combined organic phases were washed with saturated aqueous sodium chloride solution
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated to dryness
8. customThis gave 8.9 g of crude product, which was purified by chromatography on silica gel (cyclohexane-ethyl acetate 4:1)

ORD record

ord-ed49ac7b8d264d4a853318794ed441a9

Source dataset

uspto-grants-2015_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09090610B2