Reaktion #730932

Reaktionsgleichung

7-oxo-4,5,6,7-tetrahydro-benzothiazole-2-carboxylic acid ethyl ester

DMF DMA

3-guanidino-benzenesulfonamide hydrogen chloride

potassium carbonate

→

title compound

Ausbeute 24.0%

8-(3-Sulfamoyl-phenylamino)-4,5-dihydro-thiazolo [4,5-h]quinazoline-2-carboxylic acid ethyl ester

Ausbeute 24.0%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture was refluxed under nitrogen for 1 hour
2. 2
   EinengenThe reaction mixture was concentrated in vacuo
3. 3
   Sonstigethe resulting crude product (6-dimethylaminomethylene-7-oxo-4,5,6,7-tetrahydro-benzothiazole-2-carboxylic acid ethyl ester) was taken through to the next step without further purification
4. 4
   workup.DISSOLUTIONThe above was dissolved in anhydrous DMA (3 mL)
5. 5
   TemperaturThe mixture was cooled down to room temperature
6. 6
   FiltrationThe resulting solid was filtered
7. 7
   Waschenrinsed with more water
8. 8
   SonstigeThe crude solid was purified by silica gel

Vorschrift

To 7-oxo-4,5,6,7-tetrahydro-benzothiazole-2-carboxylic acid ethyl ester (0.1128 g, 0.50 mmol) was added DMF/DMA solution (3 mL) and the mixture was refluxed under nitrogen for 1 hour. The reaction mixture was concentrated in vacuo and the resulting crude product (6-dimethylaminomethylene-7-oxo-4,5,6,7-tetrahydro-benzothiazole-2-carboxylic acid ethyl ester) was taken through to the next step without further purification. The above was dissolved in anhydrous DMA (3 mL) and treated with 3-guanidino-benzenesulfonamide hydrogen chloride (128 mg, 0.51 mmol) and powdered potassium carbonate (35 mg, 0.26 mmol). The mixture was heated to 120° C. with vigorous stirring for 12 hours. The mixture was cooled down to room temperature, and diluted with water. The resulting solid was filtered, rinsed with more water, a little bit of iPrOH and Et2O. The crude solid was purified by silica gel to give the title compound as a brown solid in 24% yield (52mg). MS (ES+) 432, (ES−) 430. δH (d6 DMSO) 1.36 (3H, t), 3.05 (2H, t), 3.17 (2H, t), 4.42 (2H, q), 7.33 (2H, s), 7.41 (1H, d), 7.50 (1H, t), 7.89 (1H, d), 8.43 (1H, t), 8.52 (1H, s), 10.04 (1H, s).

Quelle