Reaktion #4998

Reaktionsgleichung

2,3-dimethylmaleic anhydride

methyl 4-amino-2-(aminosulfonyl)benzoate

→

methyl 2-(aminosulfonyl)-4-(2,5-dihydro-3,4-dimethyl-2,5-dioxo-1H-pyrrol-1-yl)benzoate

Ausbeute 43.0%

Lösungsmittel

acetic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.DISTILLATIONAcetic acid was then distilled off from the reaction mixture
2. 2
   workup.ADDITIONfollowed by the addition of 20 ml of ice water to the oily 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 acetic acid, 1 mmol of methyl 4-amino-2-(aminosulfonyl)benzoate and 1.05 mmol of 2,3-dimethylmaleic anhydride were stirred at 80° C. for 40 hours. Acetic acid was then distilled off from the reaction mixture, followed by the addition of 20 ml of ice water to the oily residue. After the mixture thus formed was stirred for 2 hours, the resulting precipitate was collected by filtration and then dried in air. Yield: 43%. Its physicochemical properties are shown in Table 8.

Quelle