4-Chloroaniline → 1-Amino-2-(4-chlorophenylazo)-naphthalene-5-sulfonamide

Participants

Reaction Conditions

Reaction Steps

A solution of 5,75 g (45,1 mmol) 4-chloroaniline in a mixture of 10 ml concentrated hydrochloric acid and 50 ml water was ice-cooled, and then diazotized with 3,17 g (45,1 mmol) sodium nitrite in 50 ml water. 10,0 g (45,0 mmol) 5-aminonaphthalene -1-sulphonamide was dissolved in a warm mixture of 200 ml 4N sulfuric acid, 300 ml acetic acid and 200 ml water. The solution was cooled to ca. 50° C., and then the diazonium salt solution was added. Stirring was continued for a few minutes, and then a solution of 180 g sodium acetate in 600 ml water was added. The pH was adjusted to ca. 5 by addition of 10N sodium hydroxide. The precipitated product was filtered off and washed with water. The crude product was recrystallized from ethanol to give 11,9 g (74%) 1-amino-2-(4-chlorophenylazo)-naphthalene-5-sulphonamide,

Provenance & Evidence