Reaction #4004

Reaction equation

2-amino-4-(2,2-dichlorovinyl)-6-hydroxypyrimidine

phosphorus oxychloride

→

2-amino-4-chloro-6-(2,2-dichlorovinyl)pyrimidine

Conditions

Workup

1. 1
   Temperatureunder reflux for 1 hour
2. 2
   TemperatureThe solution was cooled
3. 3
   Otherexcess phosphorus oxychloride was removed in vacuo on a rotary evaporator
4. 4
   workup.ADDITIONThe residual viscous oil was poured onto ice
5. 5
   workup.STIRRINGwith stirring
6. 6
   workup.ADDITIONSolid sodium bicarbonate was added portionwise until the solution
7. 7
   FiltrationThe precipitated solid was filtered
8. 8
   Washwashed with water
9. 9
   Otherdried
10. 10
    OtherRecrystallisation from aqueous methanol

Procedure

10 Parts of 2-amino-4-(2,2-dichlorovinyl)-6-hydroxypyrimidine and 66 parts of phosphorus oxychloride were heated together under reflux for 1 hour with stirring. The solution was cooled and excess phosphorus oxychloride was removed in vacuo on a rotary evaporator. The residual viscous oil was poured onto ice, with stirring. Solid sodium bicarbonate was added portionwise until the solution had pH 7-8. The precipitated solid was filtered, washed with water and dried. Recrystallisation from aqueous methanol gave 2-amino-4-chloro-6-(2,2-dichlorovinyl)pyrimidine m.p. 119°-120° C.

Source