反应详情

63 g. of iron powder are activated by heating with a mixture of 12 ml of 5N hydrochloric acid and 30 ml. of water on a water bath for half an hour, addition of 270 ml. of water and cooling the suspension to 45° C. follows. A hot solution of 58.5 g. of 4-thiocyanato-2-nitro-aniline and 180 ml. of 96% ethanol is added under stirring to the suspension formed. The temperature of the reaction mixture rises slowly. When the temperature reaches 75° C. the reaction mixture is cooled with ice in order to maintain the internal temperature below 85° C. The exothermic stage of the reaction lasts for 3-4 minutes. The reaction mixture is then heated to boiling until no more starting material can be detected by means of thin layer chromatography (about 15 minutes). The warm reaction mixture is filtered, 225 ml. of hot water are added to the filtrate, the solution is clarified with activated charcoal, filtered until warm and the filtrate is allowed to crystallize slowly under stirring. The mixture containing crystals is stirred at 0° C. for 5-6 hours, the crystals are filtered off, washed with cold 25% ethanol and dried in vacuo. Thus 41.6 g. of 4-thiocyanato-1,2-diamino-benzene are obtained, yield: 79%, M.p.: 108°-110° C.

1. additionaddition of 270 ml
2. customformed
3. customreaches 75° C.
4. temperatureis cooled with ice in order
5. temperatureto maintain the internal temperature below 85° C
6. temperatureThe reaction mixture is then heated
7. customcan be detected by means of thin layer chromatography (about 15 minutes)
8. customThe warm reaction mixture
9. filtrationis filtered
10. additionof hot water are added to the filtrate
11. filtrationfiltered
12. temperatureuntil warm
13. customto crystallize slowly
14. stirringunder stirring
15. additionThe mixture containing crystals
16. stirringis stirred at 0° C. for 5-6 hours
17. filtrationthe crystals are filtered off
18. washwashed with cold 25% ethanol
19. customdried in vacuo