Reaktion #4997

Reaktionsgleichung

5-amino-2-chlorobenzenesulfonamide

2,3-dimethylmaleic anhydride

→

2-chloro-5-(2,5-dihydro-3,4-dimethyl-2,5-dioxo-1H-pyrrol-1-yl)benzenesulfonamide

Ausbeute 93.0%

Lösungsmittel

pyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.DISTILLATIONPyridine was then distilled off from the reaction mixture
2. 2
   workup.ADDITIONfollowed by the addition of 20 ml of ice water and 0.1 ml of 35% hydrochloric acid to the solid residue
3. 3
   SonstigeAfter the mixture thus formed
4. 4
   Filtrationthe resulting precipitate was collected by filtration
5. 5
   Sonstigedried in air

Vorschrift

In 3 ml of pyridine, 1 mmol of 5-amino-2-chlorobenzenesulfonamide and 1.05 mmol of 2,3-dimethylmaleic anhydride were stirred at 90-100° C. for 9 hours. Pyridine was then distilled off from the reaction mixture, followed by the addition of 20 ml of ice water and 0.1 ml of 35% hydrochloric acid to the solid residue. After the mixture thus formed was stirred for 20 minutes, the resulting precipitate was collected by filtration and then dried in air. Yield: 93%. Its physicochemical properties are shown in Table 8.

Quelle