Malononitrile → (1-Hydroxy-2-methylpropylidene)methane-1,1-dicarbonitrile

A solution of malononitrile (19.8 g, 300 mmole) in THF (150 mL) was added dropwise to a suspension of NaH (60% dispersion in oil, 24 g, 600 mmole) in THF (375 mL) at 0° C. The reaction was then warmed to room temperature and stirred for 1 hour. The suspension was then cooled to 0° C. and treated dropwise with a solution of isobutyryl chloride (31.4 mL, 299.7 mmole) in THF (125 mL). The addition was controlled so that the internal temperature did not rise above 10° C. Upon completion of the addition, the reaction was warmed to room temperature and stirred for 24 hours. The reaction was then quenched with H2O (50 mL) and concentrated under reduced pressure. The residue was then partitioned between EtOAc (500 mL) and 5% aq. HCl (300 mL). The aqueous layer was extracted with EtOAc (250 mL), and the combined organic layers were washed with brine (500 mL), dried, filtered, and concentrated under reduced pressure. The residue was partitioned between acetonitrile (300 mL) and hexanes (100 mL). The acetonitrile layer was washed with hexanes (100 mL), and evaporated to yield the desired product (38 g, 93% yield).