3-Anilinopropionitrile → (RS)-3-Anilino-2-(2-cyclopropyl-7,8-dimethoxy-2H-1-benzopyran-5-yl-methyl)acrylonitrile

Participants

Reaction Conditions

Reaction Steps

30 g of (RS)-2-cyclopropyl-7,8-dimethoxy-2H-1-benzopyran-5-carbaldehyde and 17.5 g of 3-anilinopropionitrile were dissolved in 300 ml of dimethyl sulphoxide under argon, cooled to 10° C. and treated portionwise with 13.5 g of potassium tert.butylate. Subsequently, the mixture was stirred at 10° C. for a further 1 hr. and at 20° C. for 5 hrs. For the working up, the mixture was poured on to 3 l of ice/water and extracted: 2×3 l of ethyl acetate, 2×3 l of water. The crude product was purified by silica gel chromatography with hexane/ethyl acetate 5:1 to 2:1 and crystallized from hexane/ethyl acetate. (RS)-3-Anilino-2-(2-cyclopropyl-7,8-dimethoxy-2H-1-benzopyran-5-yl-methyl)acrylonitrile was obtained as white crystals, m.p. 140° C.

Provenance & Evidence