反应详情

360 g of N-ethyl-N-(2-hydroxyethyl)-m-toluidine and 1,250 g of water are initially introduced into a stirred flask. 196 g of concentrated sulfuric acid are added, while stirring and cooling. During this addition, the internal temperature should not rise above 50°. After cooling to 0°, 187 g of isopropyl nitrite is allowed to run in slowly at -2° to +2°. The excess of nitrite is then removed in the customary manner with amidosulfonic acid. The reaction mixture is brought to room temperature and degassed under reduced pressure. 60 g of prereduced Pd/C (5%) is added to this solution as the catalyst and the N-ethyl-N-(2-hydroxyethyl)-3-methyl-4-nitroso-aniline, which has not been isolated, is hydrogenated at 20° to 40° under a gauge pressure of 0.4 bar of hydrogen. When the reaction has ended, the reaction batch is let down, the catalyst is filtered off and the reaction mixture is concentrated.

1. temperaturecooling
2. additionDuring this addition
3. customrise above 50°
4. temperatureAfter cooling to 0°
5. customslowly at -2° to +2°
6. customThe excess of nitrite is then removed in the customary manner with amidosulfonic acid
7. customis brought to room temperature
8. customdegassed under reduced pressure
9. addition60 g of prereduced Pd/C (5%) is added to this solution as the catalyst