Reaktion #2170126

Reaktionsgleichung

2,4-diamino-6-methyl pyrimidine

sodium hydroxide

sodium nitrite

sodium nitrite

m-chloro aniline

sodium nitrite

urea

m-Chloro aniline

HCl

m-chloro aniline

pyrimidine

→

2,4-Diamino-6-methyl-5-(m-chlorophenylazo) pyrimidine

Lösungsmittel

water

—

ice-salt

water

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGAfter shaking thoroughly
2. 2
   workup.STIRRINGAfter stirring for 10 minutes
3. 3
   workup.STIRRINGAfter stirring for two hours more
4. 4
   Sonstigethe product was separated by filtration
5. 5
   Waschenwashed well with water
6. 6
   Sonstigedried in a vacuum desiccator
7. 7
   Sonstigecrystallized from ethanol

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. m-Chloro aniline (1.02 gm) was dissolved in ethanol (10 ml). To this solution 3 N HCl (30 ml) was added and the solution was cooled to -5° C. A solution of sodium nitrite (0.552 gm) in water (5 ml) was also cooled to 0° C. The cold sodium nitrite solution was then added to the cold m-chloro aniline solution. After shaking thoroughly, excess sodium nitrite was decomposed with a trace of urea. The diazotized m-chloro aniline solution 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 solution. A precipitate appeared. After stirring for two hours more, the product was separated by filtration, washed well with water, dried in a vacuum desiccator, and crystallized from ethanol. M.P. 249° C. Yield: 1.65 grams (85 percent).

Quelle