Reaktion #566021

Reaktionsgleichung

3-methyl-1-(4-methylphenyl)-3-pyrazolin-5-one

4-amino-3-hydroxybenzoic acid

hydrochloric acid

sodium nitrite

sodium hydrogen carbonate

→

3-Hydroxy-4-{[5-hydroxy-3-methyl-1-(4-methylphenyl)-1H-pyrazol-4-yl]azo}benzoic Acid

Lösungsmittel

Ethanol

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter addition the solution
2. 2
   workup.STIRRINGThe red solution was then stirred at room temperature for 16 h.

Vorschrift

A solution of 4-amino-3-hydroxybenzoic acid (0.77 g, 0.005 mol.) in 1N aqu. hydrochloric acid (15.0 mL) was cooled to 0° C. and treated slowly with a solution of sodium nitrite (0.38 g; 0.0055 mol.) in water (5.0 mL). After addition the solution was stirred at 0° C. for 10 min. then 3-methyl-1-(4-methylphenyl)-3-pyrazolin-5-one (0.94 g; 0.005 mol.) was added in one portion. Ethanol (15.0 mL) was added followed by sat. aqu. sodium hydrogen carbonate until the pH of the solution was 8 (ca. 10 mL needed). The red solution was then stirred at room temperature for 16 h.

Quelle