反应详情

温度

-30 °C

To a solution of 12.8 g (38.9 mmol) 4,5,6,7-tetrahydro-benzothiazole-2,6-diamine dihydrobromide in 220 mL concentrated aqueous hydrochloric acid at −30° C. is drop wise added 66.3 mL of an aqueous 1N solution nitrite over the course of 30 minutes. After further stirring for 1 hour at the same temperature 5.44 ml (52.5 mmol) of a 50% aqueous solution hypophosphoric acid is added. The reaction mixture is stored at 4° C. overnight. After having cooled down the solution again to −30° C. the mixture is slowly basified with 40% aqueous sodium hydroxide solution while temperature is kept at −30° C. The resulting mixture is warmed up to room temperature and extracted with Chloroform/Ethanol 5:1 (3×250 mL). The solution is dried over anhydrous sodium sulfate and concentrated in vacuum. The product obtained is chromatographically purified over silica gel, eluting with dichloromethane/methanol

1. customat −30° C.
2. customover the course of 30 minutes
3. additionis added
4. customis kept at −30° C
5. temperatureThe resulting mixture is warmed up to room temperature
6. extractionextracted with Chloroform/Ethanol 5:1 (3×250 mL)
7. dry with materialThe solution is dried over anhydrous sodium sulfate
8. concentrationconcentrated in vacuum
9. customThe product obtained
10. customis chromatographically purified over silica gel
11. washeluting with dichloromethane/methanol