Processes for the preparation of tetrakis(
View Patent ↗A process for the preparation of organic cation tetrakis( F aryl) borate salts. The process includes preparation of intermediate, mono-hydrazine substituted ( F aryl) compound, from ( F aryl) compound using hydrazine at temperatures below 78° C. A stoichiometric excess of hydrazine to the ( F aryl) compound to the ( F aryl) compound is used. The process further includes the preparation of the organic cation tetrakis( F aryl) borate in ethereal medium.
1. A process comprising:
(i) combining brominated ( F aryl) compound and alkyllithium in the presence of first solvent comprising a hydrocarbon or an ether to produce a first product;
(ii) combining at least a portion of the first product and boron trihalide in the presence of an solvent comprising ether to produce a second product; and
(iii) isolating tetrakis( F aryl) borate salt from the second product.
2. The process of claim 1 wherein the tetrakis( F aryl) borate salt comprises tetrakis(perfluoronaphthyl)borate; tetrakis(perfluoronaphth-2-yl)borate; lithium tetrakis(perfluoronaphthyl)borate, and/or lithium tetrakis(perfluoronaphth-2-yl)borate.
3. The process of claim 1 wherein the brominated( F aryl) compound comprises 2-bromoheptafluoronaphthalene.
4. The process of claim 1 wherein the alkyllithium comprises butyllithium.
5. The process of claim 1 wherein the boron trihalide comprises boron trichloride.
6. The process of claim 1 wherein (iii) comprises combining at least a portion of the second product and second solvent.
7. The process of claim 6 wherein the second solvent comprises halogenated hydrocarbon.
8. A process comprising:
(i) combining ( F aryl) compound and hydrazine in solvent below about 78° C. to form ( F aryl);
(ii) converting at least a portion of the ( F aryl) hydrazine to bromo( F aryl) compound;
(iii) combining at least a portion of the bromo( F aryl) compound and alkyllithium in a hydrocarbon or ethereal medium to form a reaction mixture;
(iv) combining boron trihalide compound and at least a portion of the reaction mixture in the presence of an ethereal medium to form lithium tetrakis( F aryl)borate; and
(v) exchanging lithium cation from at least a portion of the lithium tetrakis( F aryl)borate for cation of organic salt to form tetrakis( F aryl)borate salt.
9. The process of claim 8 wherein the ethereal medium comprises at least about 50% by volume of ether.
10. The process of claim 8 wherein the boron trihalide compound comprises boron trifluoride and/or boron trichloride.
11. The process of claim 8 wherein the alkyllithium comprises n-butyllithium, phenyllithium, methyllithium, sec-butyllithium, t-butyllithium, or hexyllithium.
12. The process of claim 8 wherein the organic salt comprises triarylmethyl salts, protic ammonium salts, or onium salts.
13. The process of claim 9 wherein the ether comprises one or more of diethyl ether, tetrahydrofuran, dioxane, dimethoxyethane, diisopropyl ether, diglyme, or methyl t-butyl ether.
14. A process comprising:
(i) combining octafluoronaphthalene and a stoichiometric excess of hydrazine in solvent below about 78° C. to form heptafluoronaphthyl hydrazine;
(ii) combining at least a portion of the heptafluoronaphthyl hydrazine and component comprising hydrogen bromide to form bromoheptafluoronaphthalene;
(iii) combining at least a portion of the bromoheptafluoronapthalene in a hydrocarbon or ethereal medium and alkyllithium to form a reaction mixture;
(iv) combining boron trihalide compound and at least a portion of the reaction mixture in an ethereal medium to form lithium tetrakis(heptafluoronaphthyl)borate in the ethereal medium;
(v) exchanging at least a portion of the ethereal medium with halogenated hydrocarbon;
(vi) exchanging lithium cation of at least a portion of the lithium tetrakis(heptafluoronaphthyl)borate with organic cation; and
(vii) precipitating tetrakis(heptafluoronaphthyl)borate salt from at least a portion of the halogenated hydrocarbon with organic cation.
15. The process of claim 14 wherein at least a portion of the solvent comprises ethanol and the temperature is between about 25° C. and about 40° C.
16. The process of claim 14 wherein the boron trihalide compound comprises boron trifluoride or boron trichloride.
17. The process of claim 14 , wherein the alkyllithium comprises n-butyllithium, phenyllithium, methyllithium, sec-butyllithium, or t-butyllithium.
18. The process of claim 14 wherein step (ii) is replaced with: (ii) combining (a) at least a portion of the heptafluoronaphthyl hydrazine and (b) component comprising hydrogen bromide and cupric bromide to form bromoheptafluoronaphthalene.