Reaktion #2170127

Reaktionsgleichung

sodium hydroxide

sodium nitrite

p-bromo aniline

2,4-diamino-6-methyl pyrimidine

p-Bromo aniline

sodium nitrite

urea

p-bromo aniline

pyrimidine

sodium nitrite

→

2,4-Diamino-6-methyl-5-(p-bromophenylazo) pyrimidine

Lösungsmittel

water

—

ice-salt

ethanol

HCl

—

solution

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   workup.STIRRINGAfter shaking thoroughly
3. 3
   workup.STIRRINGAfter stirring for 10 minutes
4. 4
   workup.STIRRINGAfter stirring for 2 hours more
5. 5
   Sonstigethe product was separated by filtration
6. 6
   Sonstigedried in vacuum desiccator
7. 7
   Sonstigecrystallized from butanol

Vorschrift

A solution of 2,4-diamino-6-methyl pyrimidine (1.0 gm) in water (60 ml) was cooled to 0° C in ice-salt bath and stirred mechanically. p-Bromo aniline (1.38 gm) was dissolved in ethanol (30 ml) and to this solution 3 N HCl (30 ml) was added. The solution was then allowed to cool to -5° C. A solution of sodium nitrite (0.553 gm) in water (5 ml) was cooled to 0° C. The sodium nitrite solution was then added to the p-bromo aniline solution. After shaking thoroughly, excess sodium nitrite was decomposed with a pinch of urea. The diazotized p-bromo aniline was then added to the pyrimidine solution. After stirring for 10 minutes, the pH of the combined solution was adjusted to 7.0 with 30 percent sodium hydroxide. A precipitate appeared. After stirring for 2 hours more, the product was separated by filtration, dried in vacuum desiccator, and crystallized from butanol. M.P. 245°-46° C. Yield: 2.2 gm (90 percent).

Quelle