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 50% 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 3 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 50% v/v isopropanol containing 6.5 g of 5% palladium-carbon over a period of 2 hours. After completion of the hydrogenation, 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 133.3 g of 4-amino-3-methyl-N-ethyl-N-(β-hydroxyethyl)aniline sulfate as white powder. Yield: 91.2%. 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