Reaktion #4540

Reaktionsgleichung

acetic acid

potassium acetate

3-chloromethyl-5-dichloromethyl-2-phthalimidopyrazine

dichloromethane

→

5-dichloromethyl-3-hydroxymethyl-2-phthalimidopyrazine

Ausbeute 47.0%

Lösungsmittel

dimethyl sulfoxide water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONthe resulting mixture was mixed thoroughly
2. 2
   Sonstigephase separation
3. 3
   WaschenThe aqueous phase was washed once with 500 ml of dichloromethane and once with 250 ml of dichloromethane
4. 4
   Waschenthe combined organic phases were washed twice with 1,000 ml of water
5. 5
   Trocknendried over sodium sulfate
6. 6
   Sonstigeevaporated down
7. 7
   SonstigeThe resulting black oil was brought to crystallization with 50 ml of methanol
8. 8
   Sonstigerecrystallized from 700 ml of methanol

Vorschrift

50 ml of glacial acetic acid and 35 g of potassium acetate were added to a solution of 57.7 g (0.16 mole) of 65% strength 3-chloromethyl-5-dichloromethyl-2-phthalimidopyrazine in 1,000 ml of a 95:5 dimethyl sulfoxide/water mixture. The mixture was stirred for three days at room temperature, after which 1,000 ml of dichloromethane and 1,000 ml of ice-water were added, the resulting mixture was mixed thoroughly and phase separation was effected. The aqueous phase was washed once with 500 ml of dichloromethane and once with 250 ml of dichloromethane, and the combined organic phases were washed twice with 1,000 ml of water, dried over sodium sulfate and evaporated down. The resulting black oil was brought to crystallization with 50 ml of methanol, and then recrystallized from 700 ml of methanol. 16.6 g (47%) of 5-dichloromethyl-3-hydroxymethyl-2-phthalimidopyrazine of melting point 191°-192° C. (sublimation with decomposition) were obtained. 1H-NMR (200 MHz, CDCl3): δ3.3 (t, OH), 4.8 (d, 2H), 6.9 (s, 1H), 8.0 (m, 4H), 9.1 (s, 1H).

Quelle