2,3-Dimethoxy-1,3-butadiene → 3,4-Dimethoxyselenophene

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a well stirred solution of 2,3-dimethoxy-1,3-butadiene (1.47 g, 12.9 mmol, (11)) and CH3COONa (2.64 g, 32.25 mmol) in dry hexane (80 mL) at −78° C. (dry ice/acetone bath), under an inert atmosphere, was added a solution of freshly prepared SeCl2 in hexane over a period of 15 min. The resulting yellowish solution was further stirred for 1 h at −78° C. and then removed from the cooling bath and the reaction mixture was brought to room temperature over a period of 2 h and further stirred for 5 h. The reaction mixture was filtered through neutral alumina and washed with hexane. The residue was concentrated to give brown yellow oil. The crude product was purified by flash column chromatography on TLC grade silica gel (Hexane:Ethyl acetate—95:5) to provide DMOS (0.85 g, 35%, (12)) as a white crystalline solid. mp. 43-45° C.

Herkunft & Nachweise