Dimethyl Sulfoxide → 3,3-Bis-methylthio-2-(2,5-dimethylbenzoyl)-acrylonitrile

Participants

Reaction Conditions

Reaction Steps

A solution of 4.96 g (28.6 mmol) of 2-cyano-2',5'-dimethylacetophenone in 120 mL of dry dimethyl sulfoxide and 3.43 mL (57.3 mmol) of carbon disulfide in a flame-dried 3-neck round bottom flask under dry nitrogen was stirred at 15°-18° C. while 1.41 g (58.7 mmol) of oil free sodium hydride was added in 5 portions. The resulting deep red solution was stirred for 1 hour at 18° C. and then cooled to 15° C. whereupon 3.92 mL (8.95 g, 63.0 mmol) of methyl iodide was added dropwise. The temperature rose to about 22° C. during the addition. After stirring for 2 hours at room temperature, the reaction mixture was poured into cold water and the aqueous layer was extracted three times with ethyl acetate. The combined extracts were washed three times with water and then dried with brine and magnesium sulfate. Evaporation gave 8.96 g of the title compound as a heavy orange oil which crystallized in the refrigerator. The analytical sample crystallized from ethanol, m.p. 74.5°-75.5° C.

Provenance & Evidence