Formaldehyde → 1-Amino-2-bromo-4-hydroxyanthraquinone

Participants

Reaction Conditions

Reaction Steps

Hydrolysis is carried out by adding 195.3 parts of 66% oleum and 16 parts of paraformaldehyde to the reaction mixture and heating it to 110° C. The mixture is heated in a stream of nitrogen to 110° C. until the presence of 1-amino-2,4-dibromoanthraquinone can no longer be detected. The reaction time is from 1 to 2 hours. Upon completion of the reaction, the reaction mixture is cooled to room temperature and diluted with 523 parts of water. The precipitated crystals of 1-amino-2-bromo-4-hydroxyanthraquinone are isolated by filtration and washed with water until neutral, affording 149 parts of product, corresponding to a yield of 93.7%, based on 1-aminoanthraquinone. Melting point: 226°-228° C. (lit.: 231°-232° C.). According to elemental analysis, the bromine content is 25.0% (calculated: 25.2%).

Provenance & Evidence