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an alkali metal salt of an organic Bronsted acid having a pk$_{0 }$ in the range of about 4 to 6, an alkali metal cyanide and an alkali metal carbonate. 

7. The process of claim 6 wherein the reaction is 5 carried out in an aprotic solvent having a dielectric constant in the range of 35 to 45. 

8. The process of claim 7 wherein the solution of the bis-maleimide of increased molecular weight is treated with a liquid which is a non-solvent for the bis-malei› mide to precipitate a solid product, and the solid prod› uct is isolated. 

9. The process of claim 1 wherein n is 0. 

10. The process of claim 1 wherein n is 1 to 20. 

11. The process of claim 1 wherein each R$_{1 }$ is hydro- gen. 

12. The process of claim 1 wherein Y is -0-. 

13. The process of claim 1 wherein each R$_{1 }$ is hydro- gen and Y is -0-. 

14. The process of claim 13 wherein the bis-malei› mide has the formula: 

15. The process of claim 13 wherein the bis-malei› mide has the formula: • 

wherein 

R$_{2 }$is -CH$_{2}$-, -0-, or -S0 2 - and 

y is a positive integer of 1 to 3. 

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