Asymmetric dianhyrdrides and methods of making the same
View Patent ↗A method for preparing asymmetric 3,4′-(hexafluroisopropylidene) dipthalic anhydride (a-6FDA) and asymmetric 3,4′-(methylene)diphthalic anhydride (a-MDPA) from asymmetric 2,3,3′,4′-benzophenone dianhydride (a-BTDA). First, a-BTDA is converted to its corresponding N-alkyl or N-phenyl bisimides by reacting with either methylamine or aniline. The sequential addition of two trifluoromethyl (CF 3 ) groups to the carbonyl unit of a-BTDA produce the corresponding bisimides of asymmetric 6FDA, which is hydrolyzed to the asymmetric 6F-tetracarboxylic acid followed by cyclodehydration to obtain asymmetric 6F-dianhydride (a-6FDA). Separately, the carbonyl unit of bisimides of a-BTDA is reduced to a methylene unit to afford the corresponding bisimides of asymmetric 3,4′-(methylene)diphthalic anhydride, which is hydrolyzed to the asymmetric methylene tetracarboxylic acid followed by cyclodehydration to obtain 3,4′-(methylene)diphthalic anhydride (a-MDPA).
1. A method of making bisimide of asymmetric benzophenone dianhydride comprising reacting asymmetric benzophenone dianhydride (a-BTDA) with an aromatic or aliphatic amine to produce a bisimide of a-BTDA having the structure depicted below:
wherein R is independently selected from phenyl, CH 3 , or C 2 H 5 , wherein the bisimide of a-BTDA is a precursor for the synthesis of a-6FDA and a-MDPA.
2. The method of claim 1 further comprising:
adding a first trifluoromethyl group (CF 3 ) via reaction with trimethy(trifluoromethyl)silane and a catalyst to a carbonyl unit of the bisimide of a-BTDA to form a first intermediate;
converting an alcohol group of the first intermediate into a halide via treatment with HX, wherein X is selected from Cl, Br, or I, to form a second intermediate;
adding second trifluoromethyl group (CF 3 ) through reaction with CF 3 Br or CF 3 I to produce a bisimide of a-6FDA, wherein the bisimide of a-6FDA has the following structure:
wherein R is independently selected from phenyl, CH 3 , or C 2 H 5 .
3. The method of claim 2 further comprising:
hydrolyzing the bisimide of a-6FDA by sodium hydroxide (NaOH) to obtain sodium salts of a-6F tetracarboxylic acid; and
acidifying the sodium salts of a-6F tetracarboxylic acid by HCl to obtain an asymmetric 6F-tetracarboxylic acid having the following structure:
4. The method of claim 3 wherein the asymmetric 6F-tetracarboxylic acid is thermally imidized by heating to about 250-300° C. to obtain a-6FDA having the structure depicted below:
5. The method claim of 3 wherein the asymmetric 6F-tetracarboxylic acid is chemical imidized by acetic anhydride to obtain a-6FDA.
6. The method of claim 1 further comprising reducing a carbonyl unit of the bisimide of a-BTDA to the methylene unit to obtain a bisimide of asymmetric (methylene)diphthalic anhydride (a-MDPA) having the structure depicted below:
wherein R is independently selected from phenyl, CH 3 , or C 2 H 5 .
7. The method of claim 6 further comprising:
hydrolyzing the bisimide of asymmetric (methylene)diphthalic anhydride (a-MDPA) by sodium hydroxide to obtain sodium salts of asymmetric methylene tetracarboxylic acid; and
acidifying the sodium salts of asymmetric methylene tetracarboxylic acid by HCl to obtain asymmetric methylene tetracarboxylic acid having the following structure:
8. The method of claim 7 wherein the asymmetric tetracarboxylic acid is thermally imidized at about 250-300° C. to obtain 3,4′-(methylene)diphthalic anhydride (a-MDPA) having the following structure:
9. The method of claim 7 wherein the asymmetric tetracarboxylic acid is chemical imidized by acetic anhydride to obtain 3,4′-(methylene)diphthalic anhydride (a-MDPA).
10. A method of making asymmetric 3, 4′-(hexafluroisopropylidene)diphthalic anhydride (a-6FDA) comprising:
reacting asymmetric benzophenone dianhydride (a-BTDA) with an aromatic or aliphatic amine to produce a bisimide of a-BTDA having the structure depicted below:
wherein R is independently selected from phenyl, CH 3 , or C 2 H 5 ;
adding a first trifluoromethyl group (CF 3 ) via reaction with trimethy(trifluoromethyl)silane to a carbonyl unit of the bisimide of a-BTDA to form a first intermediate;
converting an alcohol group of the first intermediate into a halide via treatment with HX, wherein X is selected from Cl, Br, or I, to form a second intermediate;
adding second trifluoromethyl group (CF 3 ) through reaction with CF 3 Br or CF 3 I to produce a bisimide of a-6FDA, wherein the bisimide of a-6FDA has the following structure:
wherein R is independently selected from phenyl, CH 3 , or C 2 H 5 .
11. The method of claim 10 further comprising:
hydrolyzing the bisimide of a-6FDA to obtain sodium salts of a-6F tetracarboxylic acid; and acidifying the sodium salts of a-6F tetracarboxylic acid to obtain an asymmetric 6F-tetracarboxylic acid having the following structure:
12. The method of claim 11 , wherein the bisimide of a-6FDA is hydrolyzed by sodium hydroxide (NaOH).
13. The method of claim 11 , wherein the sodium salts of a-6F tetracarboxylic acid are acidified by HCl.
14. The method of claim 11 wherein the asymmetric 6F-tetracarboxylic acid is thermally imidized by heating to about 250-300° C. to obtain a-6FDA, having the structure depicted below:
15. The method claim of 11 wherein the asymmetric 6F-tetracarboxylic acid is chemical imidized by acetic anhydride to obtain a-6FDA.
16. A method of making asymmetric 3,4′-(methylene)diphthalic anhydride (a-MDPA) comprising:
reacting asymmetric benzophenone dianhydride (a-BTDA) with an aromatic or aliphatic amine to produce a bisimide of a-BTDA having the structure depicted below:
wherein R is independently selected from phenyl, CH 3 , or C 2 H 5 ;
reducing a carbonyl unit of the bisimide of a-BTDA to a methylene unit to obtain a bisimide of asymmetric (methylene)diphthalic anhydride (a-MDPA); and
hydrolyzing the bisimide of asymmetric (methylene)diphthalic anhydride (a-MDPA) to obtain sodium salts of asymmetric methylene tetracarboxylic acid; and
acidifying the sodium salts of asymmetric methylene tetracarboxylic acid to obtain asymmetric methylene tetracarboxylic acid having the following structure:
17. The method of claim 16 , wherein the bisimide of asymmetric (methylene)diphthalic anhydride is hydrolyzed by sodium hydroxide (NaOH).
18. The method of claim 16 , wherein the sodium salts of asymmetric methylene tetracarboxylic acid are acidified by HCl.
19. The method of claim 16 wherein the asymmetric tetracarboxylic acid is thermally imidized at about 250-300° C. to obtain 3,4′-(methylene)diphthalic anhydride (a-MDPA), having the following structure:
20. The method of claim 16 , wherein the asymmetric tetracarboxylic acid is chemical imidized by acetic anhydride to obtain 3,4′-(methylene)diphthalic anhydride (a-MDPA).