Sulfuric Acid → Ethanol, 2-((4-amino-3-methylphenyl)ethylamino)-, sulfate (1:1)

Participants

Reaction Conditions

Reaction Steps

With 89.6 g (0.5 mole) of N-ethyl-N-(β-hydroxyethyl)-m-toluidine was mixed 270 ml of 70% v/v isopropanol, and 24.5 g (0.25 mole) of sulfuric acid was added with cooling and stirring at 10° C. or lower. After 49.0 g (0.55 mole) of isopropyl nitrite was added dropwise at 10° C. or lower, the reaction was carried out at 2°-5° C. for another 4 hours. After completion of the reaction, hydrogenation was carried out at 40°-45° C. and at a hydrogen pressure of 3-5 kg/cm2 while adding the nitrosation reaction mixture to 270 ml of 70% v/v isopropanol containing 6.5 g of 5% palladium-carbon over a period of 1.5 hours. After completion of the hydrogenation reaction, the catalyst was filtered off and the filtrate was concentrated to dryness to remove the solvent. The residue was dissolved in 270 ml of 90% v/v ethanol with heating and 24.5 g (0.25 mole) of sulfuric acid was added at 45°-50° C. Then, the resulting mixture was cooled for 2 hours to carry out crystallization, and the crystals thus formed were collected by filtration at 3° C., washed with 100 ml of cold ethanol, and then dried to obtain 132.7 g of 4-amino-3-methyl-N-ethyl-N-(β-hydroxyethyl)aniline sulfate as white powder. Yield: 90.8%. Melting point: 154.6° C. The purity of 4-amino-3-methyl-N-ethyl-N-(β-hydroxyethyl)aniline sulfate was 100% as measured by HPLC, namely, no impurity was detected at all.

Provenance & Evidence