反应 #2029575

反应方程式

sodium hydroxide

N6-propyl-4,5,6,7-tetrahydro-benzothiazole-2,6-diamine dihydrobromide

hypophosphoric acid

nitrite

→

propyl-(4,5,6,7-tetrahydro-benzothiazol-6-yl)-amine

溶剂

hydrochloric acid

反应条件

后处理

1. 1
   其他at −30° C.
2. 2
   其他over the course of 30 minutes
3. 3
   workup.ADDITIONis added
4. 4
   其他is kept at −30° C
5. 5
   温度The resulting mixture is warmed up to room temperature
6. 6
   萃取extracted with chloroform/ethanol 5:1 (3×250 mL)
7. 7
   干燥The solution is dried over anhydrous sodium sulfate
8. 8
   浓缩concentrated in vacuum
9. 9
   其他The brown oil obtained
10. 10
    其他is chromatographed over silica gel
11. 11
    洗涤eluting with dichloromethane/methanol 97:3 under ammonia atmosphere

实验过程

To a solution of 14.5 g (38.9 mmol) N6-propyl-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 brown oil obtained is chromatographed over silica gel, eluting with dichloromethane/methanol 97:3 under ammonia atmosphere.

来源