[omido2]

i want to synthesis m-phenylenedimaleimide,i add molten maleic anhydride to solution of m-phenylenediamine(black color) in acetone,solid material is achieved
(i think it is n,n'-m-phenylenedimaleamic acid),i heat a mixture of this acid,acetic anhydride,anhydrous sodium acetate,acetone at 50-60 C for a period of one hour.after that let the reaction is cooled to room tempearature,equal volume of water is added with stirring ,after i filter the solution ,no product is achieved.

i do not know what is my mistake

note:metaphenylene diamine is originally white,but it is sensitve to air and tend to darken,metaphenylene diamine that i use is completely black

[GCT]

You might get more replies if you would post an attachment of the some of the molecules involved.

[movies]

So do you know what you did get out of the reaction?

[omido2]

i followed us patent 3,127,414

[DrCMS]

Try this:

React maleic anhydride 2.2mole with m-phenylenediamine 1mole in acetone ~7moles. To control the exotherm, the diamine in solvent is added slowly, forming the dicarboxylic acid intermediate.  Keep temp <50°C.

After half an hour stirring add triethylamine ~0.5moles, acetic anhydride ~2.5moles, magnesium sulfate~0.02moles, acetone ~1mole and water ~0.5 moles to promote cyclisation into m-phenylenebismaleimide.  React ~40°C ~4hrs cool to 25°C and get a yellow solid.

[omido2]

 ::)thanks for your help

i 'll follow your suggested procedure but i want to know
does m-phenylenediamine degradation by oxidation process
(that is influenced by air) have any effect on this synthesis or not ?i mean my failure in first method because of that or not?

see these links

http://www.dupont.com.br/adm/port/upload_produto_pdf/MPD%20Tech%20Sheet.pdf

http://www.dupont.com/specintermediates/mpd_color.html

[DrCMS]

Don't worry too much about MPD oxidation prior to the reaction i've used black MPD and made OK maleimide before.  Do the reaction under nitrogen to be on the safe side tho.  My guess is that you made the di acid ok but it did not cyclise under the conditions you used.  

[omido2]

 ;Dthanks