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

Temperature

-78 °C

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.

1. customremoved from the cooling bath
2. waitthe reaction mixture was brought to room temperature over a period of 2 h
3. stirringfurther stirred for 5 h
4. filtrationThe reaction mixture was filtered through neutral alumina
5. washwashed with hexane
6. concentrationThe residue was concentrated
7. customto give brown yellow oil
8. customThe crude product was purified by flash column chromatography on TLC grade silica gel (Hexane:Ethyl acetate—95:5)

ORD record

ord-18f9441165df4406b6d2489b4d5df025

Source dataset

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08822635B2