Reaction #1262

Reaction equation

4-chloro-2,6-diaminopyrimidine

sodium acetate

4-chlorobenzenediazonium chloride

→

6-chloro-5-[(4-chlorophenyl)azo]-2,4-pyrimidinediamine

Yield 41.4%

Solvents

water

acetic acid

Conditions

Workup

1. 1
   Temperaturewith cooling over 30 minutes at a rate that
2. 2
   Otherthe reaction at 18°
3. 3
   workup.STIRRINGThe reaction was stirred overnight at room temperature
4. 4
   Filtrationthe orange crystals were filtered
5. 5
   Washwashed with water (4×400 ml)
6. 6
   Otherdried in vacuo

Procedure

To a suspension of 4-chloro-2,6-diaminopyrimidine (21.68 g, 0.150 mol) in water (750 ml) and acetic acid (750 ml) was added sodium acetate (300 g). Solution occurred after stirring for 20 minutes, and then the solution of 4-chlorobenzenediazonium chloride (0.166 mol) was added with cooling over 30 minutes at a rate that kept the reaction at 18°. The reaction was stirred overnight at room temperature, and the orange crystals were filtered, washed with water (4×400 ml), and dried in vacuo to give 17.6 g of 6-chloro-5-[(4-chlorophenyl)azo]-2,4-pyrimidinediamine. The mother liquors were cooled to 5° for 20 hours, and the crystals were collected and dried in vacuo to give 6.94 g of additional 6-chloro-5-[(4-chlorophenyl)azo]-2,4-pyrimidineadiamine.

Source