Reaktion #332316

Reaktionsgleichung

4-(methylthio)aniline

diethyl ethanedioate

HCl

→

5-(methylthio)-1H-indole-2,3-dione

Ausbeute 10.0%

Lösungsmittel

acetic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was cooled to room temperature
2. 2
   workup.WAITto stand overnight, at which time
3. 3
   Sonstigethe product had crystallized
4. 4
   FiltrationThe crystals were collected by filtration
5. 5
   Waschenwashed with minimal acetic acid
6. 6
   workup.DISSOLUTIONThe crystals were dissolved in 5% sodium hydroxide (150 mL)
7. 7
   Temperaturthe solution was heated to 90° C
8. 8
   SonstigeAir was bubbled through the solution continuously
9. 9
   Sonstigeforming a yellow solution
10. 10
    workup.WAITAfter 8 hours
11. 11
    Temperaturthe solution was cooled
12. 12
    FiltrationThe precipitate was collected by filtration
13. 13
    Waschenwas washed with water
14. 14
    Sonstigedried

Vorschrift

A mixture of 4-(methylthio)aniline (13.92 g, 100 mmol) and diethyl ethanedioate (17.42 g, 100 mmol) in acetic acid (50 mL) was stirred at 90° C. for 8 h. The mixture was cooled to room temperature and allowed to stand overnight, at which time the product had crystallized. The crystals were collected by filtration and washed with minimal acetic acid. The crystals were dissolved in 5% sodium hydroxide (150 mL), and the solution was heated to 90° C. Air was bubbled through the solution continuously, forming a yellow solution. After 8 hours, the solution was cooled and acidified with concentrated HCl. The precipitate was collected by filtration and was washed with water and dried to afford 5-(methylthio)-1H-indole-2,3-dione (1.9 g, 10% yield). MS (m/z) 194.0 (M+H+).

Quelle