PREPARATION OF DI-CATION ETHERS

• Main Authors: CHAPMAN; DEREK D, VALENTE; RONALD R
• Format: Patent
• Language: English
• Published: 05.05.1992
• Subjects: CHEMISTRY; HETEROCYCLIC COMPOUNDS; METALLURGY; ORGANIC CHEMISTRY

Di-cation ether salts are prepared by a reaction sequence which comprises (i) N-alkylating a 2-halopyridine, (ii) reacting the N-alkylated product with a 2-hydroxypyridine in the presence of sufficient organic base to combine with the by-product hydrohalic acid, and (iii) reacting the mono-cation ether thereby produced with an alkylating agent. The process is conducted in the presence of a solvent, such as acetonitrile. The di-cation can be isolated by removal of the solvent, followed by contacting the reaction mixture with an aqueous fluoborate, whereby the di-cation ether precipitates as the fluoborate salt. The di-cation ether is prepared in surprisingly high yield. The process can be conducted in one reaction vessel without isolation of a product intermediate formed in the reaction sequence. The fluoborate product is quite pure. If desired, the fluoborate anion can be removed from the di-cation ether by suspending the di-cation ether fluoborate in water, and reacting it with a potassium salt such as KNO3. The soluble di-cation product thereby produced can be used as a gelatin hardener, or as a chemical intermediate.