Reaction #323571

Reaction equation

p-phenylenediamine

tetrabromophthalic anhydride

→

N,N'-(p-phenylene)-bis[3,4,5,6-tetrabromophthalimide]

Solvents

NMP

NMP

Conditions

Workup

1. 1
   Filtrationthe solution filtered
2. 2
   Otherto remove
3. 3
   workup.ADDITIONThis filtered solution was then added to
4. 4
   Othera similarly prepared
5. 5
   OtherA mildly exothermic reaction
6. 6
   Temperaturethe mixture was further heated
7. 7
   OtherAt about 145° C., precipitation
8. 8
   TemperatureThe quantity of brown precipitate increased
9. 9
   Temperaturewith continued heating
10. 10
    workup.ADDITIONa further 2 liters of NMP was added
11. 11
    workup.STIRRINGto facilitate stirring
12. 12
    Temperaturemaintained for 2 hours, before the mixture
13. 13
    Temperatureto cool
14. 14
    OtherThe precipitate was collected
15. 15
    Washwashed with NMP
16. 16
    Otherroughly dried
17. 17
    Washwashed with acetone
18. 18
    workup.STIRRINGThe material was then stirred well with acetone
19. 19
    Filtrationfiltered
20. 20
    Washagain washed
21. 21
    Otherbefore being dried overnight at 150° C. under vacuum
22. 22
    Otherthe characteristic imide structure, absorption bands at 1712s and 1765w cm-1

Procedure

108 gms (1.0 mole) of p-phenylenediamine was dissolved in 1 liter of warm NMP under a nitrogen atmosphere and the solution filtered to remove suspended particles. This filtered solution was then added to a similarly prepared filtered solution of 928 gms (2.0 moles) of tetrabromophthalic anhydride in 2 liters of warm NMP in the apparatus described in Example 2. A mildly exothermic reaction took place and the mixture was further heated while stirring. At about 145° C., precipitation began. The quantity of brown precipitate increased with continued heating and a further 2 liters of NMP was added to facilitate stirring, the temperature being raised to 200° C. and maintained for 2 hours, before the mixture was allowed to cool. The precipitate was collected, washed with NMP, roughly dried and washed with acetone. The material was then stirred well with acetone, filtered and again washed before being dried overnight at 150° C. under vacuum. The product was a fine, rusty-gold precipitate with a melting point above 500° C. The yield was 486 gms (49%), the infrared spectrum having the characteristic imide structure, absorption bands at 1712s and 1765w cm-1. The compound was insoluble in water, methanol, ether, xylene, dimethyl sulphoxide and dimethyl acetamide.

Source