Reaktion #171154

Reaktionsgleichung

hydrochloric acid

2-thiophenenitrile

diisopropyl succinate

potassium tert-butoxide

→

3,6-bis(thiophen-2-yl)-2H,5H-pyrrolo[3,4-c]pyrrole-1,4-dione

Ausbeute 82.7%

Lösungsmittel

water

methanol

methanol

tert-amyl alcohol

tert-amyl alcohol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeequipped with a mechanical stirrer
2. 2
   workup.ADDITIONis added dropwise over a period of 3 h with rapid stirring
3. 3
   Temperaturcooled to 50° C., at which point
4. 4
   workup.ADDITIONis added
5. 5
   TemperaturThe reaction mixture is heated
6. 6
   Temperaturat reflux for 45 min
7. 7
   Temperaturbefore cooling to room temperature
8. 8
   workup.STIRRINGthe mixture is stirred for 45 min
9. 9
   FiltrationThe mixture is filtered
10. 10
    Waschenthe solid is washed with methanol (200 mL)
11. 11
    workup.STIRRINGstirred for 30 min
12. 12
    Filtrationbefore being filtered again
13. 13
    workup.STIRRINGThis suspension in water, stirring
14. 14
    Filtrationfiltration
15. 15
    FiltrationAfter filtering for the last time
16. 16
    Sonstigedried at 80° C. for 16 h
17. 17
    Sonstigedried under vacuum

Vorschrift

As a specific example embodiment, potassium tert-butoxide (67.4 g, 0.60 mol) and tert-amyl alcohol (400 mL) are added to a nitrogen-protected oven-dried three-neck round-bottom flask equipped with a mechanical stirrer, a thermometer and a reflux condenser. The mixture is heated to 105° C. for 1.5 h and to this mixture is added 2-thiophenenitrile (55.2 g, 0.50 mol) and the stirring continued at 105° C. for 30 min. A mixture of diisopropyl succinate (40.4 g, 0.20 mol) in tert-amyl alcohol (60 mL) is added dropwise over a period of 3 h with rapid stirring. The mixture is then stirred at 105° C. for a further 2 h, then cooled to 50° C., at which point a mixture of methanol (300 mL) and water (80 mL) is added. The reaction mixture is heated at reflux for 45 min before cooling to room temperature. The mixture is poured over 500 g of ice, then concentrated hydrochloric acid (35% aq) (150 mL) and methanol (750 mL) are added and the mixture is stirred for 45 min. The mixture is filtered and the solid is washed with methanol (200 mL). The solid is then suspended in water (1 L) and stirred for 30 min before being filtered again. This suspension in water, stirring and filtration is repeated a further three times. After filtering for the last time, the solid is oven dried at 80° C. for 16 h, then dried under vacuum to give the product, 3,6-bis(thiophen-2-yl)-2H,5H-pyrrolo[3,4-c]pyrrole-1,4-dione, (49.7 g, 82% yield) as a red solid. This compound is used without further purification. 1HNMR (d6-DMSO, 300 MHz): δ 7.27 (2H, t, J=3.0), 7.89 (2H, dd, J1=6.0, J2=3.0), 8.23 (2H, d, J=3.0), 11.00 (2H, s); 13CNMR (d6-DMSO, 75 MHz): δ 113.6 (2C), 127.1 (2C), 128.3 (2C), 130.5 (2C), 136.6 (2C), 142.6 (2C), 168.2 (2C); m/z (EI+) 300.0 [M]+; Anal. Calc. for C14H8N2O2S2: C, 55.98; H, 2.68; N, 9.33; S, 21.35.

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