N-methyl-2-pyrrolidone → 2-Hydroxy-3,6-bis(2,5-dimethoxy-4-benzoylaminophenylaminocarbonyl)naphthalene

Participants

Reaction Conditions

Reaction Steps

2,5-Dimethoxy-4-benzoylaminoaniline (16.6 g), N-methyl-2-pyrrolidone (111.2 g) and toluene (30.1 g) were dissolved at room temperature and the acid chloride (5.5 g) obtained in Example 6 was gradually added, and then the mixture was amidated according to Example 8. After the reaction solution was cooled to 25° C. and filtered, toluene was distilled off under reduced pressure. Then, the solution was crystallized by using methanol (377.2 g). The resultant product was subjected to reflux washing using methanol (250.0 g) for 1 hour, filtered and then dried to obtain 12.4 g of 2-hydroxy-3,6-bis(2,5-dimethoxy-4-benzoylaminophenyl-aminocarbonyl)naphthalene as a dull yellow powdered crystal (DSC analysis value: 327.4° C.).

Provenance & Evidence