Reacción #53591

Ecuación de reacción

7-amino-1-hydroxy-3-naphthalene sulfonic acid

sodium hydrosulfite

HCl

sodium sulfanilate

sodium nitrite

→

title compound

Rendimiento 45.0%

7,8-Diamino-1-hydroxy-3-naphthalene sulfonic acid dihydrochloride

Rendimiento 45.0%

Disolventes

water

water

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe reaction mixture was warmed to 50° C.
2. 2
   workup.STIRRINGthe reaction was stirred for 4 hours
3. 3
   FiltraciónThe reaction was filtered
4. 4
   Lavadothe precipitate was washed with water, methanol, and ether

Procedimiento

A stirred solution of p-benzenediazonium sulfonic acid, was prepared by the addition of sodium sulfanilate (1.10 g, 5.2 mmole) to sodium nitrite (0.40 g, 5.7 mmole) in water (10 mL) followed by addition to ice (6.0 g) and concentrated HCl (1.1 mL, 37%). After 30 min. of standing at 0° C. 7-amino-1-hydroxy-3-naphthalene sulfonic acid (1.2 g, 5.2 mmole) was added in water (10 mL) and the reaction was stirred at room temperature overnight. The reaction mixture was warmed to 50° C. and sodium hydrosulfite (3.0 g, 15.6 mmole) was added and the reaction was stirred for 4 hours. The reaction was filtered and the precipitate was washed with water, methanol, and ether to give the title compound (0.54 g; 45%) as a red solid. MS(ES) m/z 255 [M+H].

Fuente