Diethyl (cyanomethyl)phosphonate → 2-(1,1-dioxidodihydro-2H-thiopyran-4(3H)-ylidene)acetonitrile

Participants

Reaction Conditions

Reaction Steps

Potassium tert-butoxide (3.5 mL, 3.5 mmol, 1.0 M in THF) was stirred at 0° C. and THF (8 mL) was added. Diethyl (cyanomethyl)phosphonate (0.56 mL, 3.5 mmol) was added slowly by syringe. The reaction mixture was maintained at 0° C. for 10 minutes, then warmed to ambient temperature and maintained for 1 hour. The mixture was cooled to 0° C. and treated with the dropwise addition of dihydro-2H-thiopyran-4(3H)-one 1,1-dioxide (0.50 g, 3.4 mmol) in THF (5 mL). After addition, the mixture was maintained at 0° C. for 20 minutes, then warmed to ambient temperature and maintained for 18 hours. The reaction mixture was then diluted with water and extracted with EtOAc. The combined organic extracts were washed with water, brine, dried over anhydrous Na2SO4, filtered, and concentrated in vacuo. The residue was purified MPLC on silica gel (using a gradient elution of 0-50% EtOAc/hexanes). Desired fractions were identified, combined, and concentrated in vacuo to the title compound.

Provenance & Evidence