Reaktion #66818

Reaktionsgleichung

sodium chloride

sulfolane

phosphoryl chloride

tert-Butyl 3-cyano-4-hydroxy-5,8-dihydrothieno[2,3-b:5,4-c′]dipyridine-7(6H)-carboxylate

→

title compound

Ausbeute 51.0%

tert-Butyl 4-chloro-3-cyano-5,8-dihydrothieno[2,3-b:5,4-c′]dipyridine-7(6H)-carboxylate

Ausbeute 51.0%

Lösungsmittel

Triethylamine

triethylamine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwith cooling
2. 2
   TemperaturThe mixture was cooled to rt
3. 3
   Temperaturwhilst cooling with an ice-bath
4. 4
   Extraktionextracted with ethyl acetate
5. 5
   WaschenThe organic layer was washed with water
6. 6
   Trocknendried over sodium sulfate
7. 7
   Sonstigethe solvent was removed in vacuo
8. 8
   workup.ADDITIONToluene was added
9. 9
   Waschenthe mixture was washed with water
10. 10
    TrocknenThe organic layer was again dried over sodium sulfate
11. 11
    Sonstigethe solvent was removed in vacuo
12. 12
    SonstigeAfter crystallization
13. 13
    Sonstigethe product was triturated with water
14. 14
    Filtrationcollected by suction filtration
15. 15
    Sonstigedried

Vorschrift

To sulfolane (10 mL) was added phosphoryl chloride (1.39 g, 9.05 mmol) at rt. Triethylamine (0.92 g, 9.05 mmol) was added dropwise with cooling. tert-Butyl 3-cyano-4-hydroxy-5,8-dihydrothieno[2,3-b:5,4-c′]dipyridine-7(6H)-carboxylate from Example 52A (1.00 g, 3.02 mol) was added, and the mixture was heated to 70° C. for 1.5 h. The mixture was cooled to rt, and triethylamine (2.3 mL) was added. A semi-saturated aqueous sodium chloride solution (10 L) was added whilst cooling with an ice-bath. The mixture was stirred at rt for 30 min and then extracted with ethyl acetate. The organic layer was washed with water, dried over sodium sulfate, and the solvent was removed in vacuo. Toluene was added, and the mixture was washed with water. The organic layer was again dried over sodium sulfate, and the solvent was removed in vacuo. After crystallization, the product was triturated with water, collected by suction filtration and dried to yield 543 mg (51%) of the title compound.

Quelle