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

HRID 1165823Notes

Reaction equation

[Cl:1][C:2]1[CH:8]=[CH:7][C:5]([NH2:6])=[CH:4][CH:3]=1.[N:9]([O-])=O.[Na+].[NH2:13][C:14]1[CH:23]=[CH:22][CH:21]=[C:20]2[C:15]=1[CH:16]=[CH:17][CH:18]=[C:19]2[S:24]([NH2:27])(=[O:26])=[O:25].C([O-])(=O)C.[Na+].[OH-].[Na+]>Cl.O.S(=O)(=O)(O)O.C(O)(=O)C>[NH2:13][C:14]1[C:15]2[CH:16]=[CH:17][CH:18]=[C:19]([S:24]([NH2:27])(=[O:25])=[O:26])[C:20]=2[CH:21]=[CH:22][C:23]=1[N:9]=[N:6][C:5]1[CH:7]=[CH:8][C:2]([Cl:1])=[CH:3][CH:4]=1

Participants

Conditions

Temperature: 50 °C

Procedure

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, m.p. 258° C.

Workup

temperaturecooled
waitwas continued for a few minutes
filtrationThe precipitated product was filtered off
washwashed with water
customThe crude product was recrystallized from ethanol

Sources & evidence

ORD record: ord-d0f89963ee4a43b6a8e41cb62ce06c6f
Source dataset: uspto-grants-1990_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04912108

Reaction notes

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