Reaktion #792069

Reaktionsgleichung

5-(4-chlorobenzoyl)-2-chloro-1-[2-(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-yl)ethyl]pyrrole sodium salt

methanol

methanol

→

5-(4-chlorobenzoyl)-2-chloro-1-[3,3-di(methoxycarbonyl)propyl]pyrrole

Lösungsmittel

hydrogen chloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto warm to room temperature
2. 2
   workup.STIRRINGwas then stirred for another four hours
3. 3
   SonstigeThe solvent was then evaporated under reduced pressure at 10°-20° C
4. 4
   SonstigeThe residue was partitioned between ether and water (150 ml+150 ml)
5. 5
   Extraktionthe water was extracted with ether (2×150 ml)
6. 6
   TrocknenThe combined ether extracts were dried over anhydrous sodium sulfate
7. 7
   Sonstigeevaporated to dryness
8. 8
   SonstigeThe residue was chromatographed on Florisil® (50 g/g mixture)
9. 9
   Wascheneluting the product with hexane/ethyl acetate, 7:3
10. 10
    SonstigeThe product so obtained (1.912 g, 68%)
11. 11
    Sonstigewas recrystallized from dichloromethane/hexane

Vorschrift

The 5-(4-chlorobenzoyl)-2-chloro-1-[2-(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-yl)ethyl]pyrrole sodium salt from Example 3A was dissolved in methanol saturated with hydrogen chloride (30 ml) and stirred at 0° C. for three hours. The solution was diluted with methanol (30 ml) and allowed to warm to room temperature, and was then stirred for another four hours. The solvent was then evaporated under reduced pressure at 10°-20° C. The residue was partitioned between ether and water (150 ml+150 ml), and the water was extracted with ether (2×150 ml). The combined ether extracts were dried over anhydrous sodium sulfate and evaporated to dryness. The residue was chromatographed on Florisil® (50 g/g mixture), eluting the product with hexane/ethyl acetate, 7:3. The product so obtained (1.912 g, 68%) was a colorless crystalline solid, which was recrystallized from dichloromethane/hexane to afford 5-(4-chlorobenzoyl)-2-chloro-1-[3,3-di(methoxycarbonyl)propyl]pyrrole, having the following properties:

Quelle