Reaktion #74944

Reaktionsgleichung

hydrogen sulfide

1,2-diphenyl-4-(2,4-dimethoxyphenyl)butane-1,4-dione

phosphorus pentasulfide

hydrogen sulfide

sodium hydroxide

→

2,3-diphenyl-5-(2,4-dimethoxyphenyl)thiophene

Ausbeute 61.9%

Lösungsmittel

ethanol

xylene

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe autoclave was then cooled
2. 2
   Sonstigeto destroy excess phosphorus pentasulfide
3. 3
   Filtrationfiltration
4. 4
   Sonstigegave 27.6 g (49.4%) of crude product, m.p. 107°-110° C
5. 5
   SonstigeRecrystallization from 30 ml of dioxane and 60 mll of ethanol

Vorschrift

In a 1-l stainless steel autoclave were placed 56.2 g (0.150 mole) of 1,2-diphenyl-4-(2,4-dimethoxyphenyl)butane-1,4-dione, 100 ml of xylene, 33.3 g (0.075 mole) of phosphorus pentasulfide and 120 g of hydrogen sulfide. The contents of the autoclave were stirred at 160°-162° C. (1040-1080 psig) for three hours. The autoclave was then cooled, and the remaining hydrogen sulfide was vented into a trap of aqueous sodium hydroxide. The residue was stirred with 150 ml of absolute ethanol to destroy excess phosphorus pentasulfide. Chilling to -78° C. and filtration gave 27.6 g (49.4%) of crude product, m.p. 107°-110° C. Recrystallization from 30 ml of dioxane and 60 mll of ethanol gave 17.3 g (31%) of pure 2,3-diphenyl-5-(2,4-dimethoxyphenyl)thiophene, m.p. 112°-114° C.

Quelle