Reaktion #2129717

Reaktionsgleichung

NH2NH2.H2O

3-thiophenecarboxylic acid

LDA

KMnO4

p-anisaldehyde

→

7-(4-Methoxy-phenyl)-5H-thieno[2,3-d]pyridazin-4-one

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe solvent was evaporated
2. 2
   WaschenThe aqueous solution was washed with EtOAc (2×40 mL)
3. 3
   Sonstigedropwise at 0° C
4. 4
   SonstigeThe ice-bath was removed
5. 5
   Temperaturthe reaction was heated to 60° C. for 3 h
6. 6
   SonstigeThe solid was collected
7. 7
   Waschenwashed with hot water
8. 8
   Extraktionextracted with EtOAc (3×50 mL)
9. 9
   TrocknenThe combined EtOAc was dried
10. 10
    Sonstigeevaporated
11. 11
    workup.DISSOLUTIONThe crude solid was dissolved in 50 mL of EtOH
12. 12
    TemperaturThe reaction was heated to 80° C. for 3 h
13. 13
    Sonstigethe resulting solid was collected
14. 14
    Waschenwashed with EtOH
15. 15
    Sonstigeto give 3.6 g (36%)

Vorschrift

A solution of 3-thiophenecarboxylic acid (10 g, 78 mmol) in 250 mL of THF at 0° C. under N2 was added 2.0 M LDA (2.2 eq., 86 mL) dropwise. After 10 min at 0° C., p-anisaldehyde (10.6 mL, 1.12 eq.) was added and the mixture was slowly warmed to room temperature overnight. The reaction was stirred for ˜14 h, after which 100 mL of ice-water was added, and the solvent was evaporated. The aqueous solution was washed with EtOAc (2×40 mL), and then added KMnO4 (2 eq., 12.4 g) dropwise at 0° C. The ice-bath was removed and the reaction was heated to 60° C. for 3 h. The solid was collected and washed with hot water. The aqueous layer was acidified to pH ˜3, extracted with EtOAc (3×50 mL). The combined EtOAc was dried and evaporated. The crude solid was dissolved in 50 mL of EtOH, and NH2NH2.H2O (1.5 eq., 1.5 mL) was added dropwise. The reaction was heated to 80° C. for 3 h, and the resulting solid was collected and washed with EtOH to give 3.6 g (36%): MS m/z 259 (M+H).

Quelle