Reaktion #709406

Reaktionsgleichung

(3-bromothien-2-yl) (4-methoxyphenyl)methanone hydrazone

potassium hydroxide

→

oil

3-(4-Methoxyphenyl)-1H-thieno[3,2-c]pyrazole

Lösungsmittel

ethoxyethanol

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeprepared
2. 2
   TemperaturThe darkened mixture was maintained at 105°-110° C. for an additional 90 minutes
3. 3
   Sonstigequenched with water
4. 4
   ExtraktionThe organic materials were extracted exhaustively with ethyl acetate/ether (1:1)
5. 5
   Waschenthe combined organic solution was washed (four times) with water
6. 6
   Sonstigedried
7. 7
   SonstigeEvaporation of the solvents
8. 8
   Sonstigeafforded a thick oil which
9. 9
   Sonstigewas purified by passage through an alumina column
10. 10
    WaschenElution with ether
11. 11
    Sonstigeremoved most of the dark impurities and further elution with 5% methanol/ether

Vorschrift

A solution of 1.0 g of (3-bromothien-2-yl) (4-methoxyphenyl)methanone hydrazone in 60 ml of ethoxyethanol was treated with an alkaline solution prepared by dissolving 6.0 g of 85% potassium hydroxide pellets in 20 ml of water. The resultant solution was stirred at 105°-110° for 30 minutes and to it under nitrogen was added 250 ml of finely powdered cuprous chloride. The darkened mixture was maintained at 105°-110° C. for an additional 90 minutes and quenched with water. The organic materials were extracted exhaustively with ethyl acetate/ether (1:1) and the combined organic solution was washed (four times) with water and dried. Evaporation of the solvents afforded a thick oil which was purified by passage through an alumina column. Elution with ether removed most of the dark impurities and further elution with 5% methanol/ether gave 5.2 g of an oil which solidified on scratching, m.p. 143°-144° C. For analysis, a small sample was recrystallized from ether/hexane without any change in the melting range.

Quelle