Method of production and method of separation of 2,4'-dipyridyl derivatives and methods of production of benzoxazepine derivatives and salts thereof
AssigneeDaiichi Suntory Pharma Co., Ltd.
InventorsToshio Tatsuoka, Katsuhide Kamei
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Abstract
A method of production of 2,4′-dipyridyl derivatives by a cross coupling reaction of a 2-halopyridine derivative and a 4-halopyridine using a nickel complex catalyst and a method of separation of a 2,4′-dipyridyl derivative from a mixture of dipyridyl isomers containing a 2,2′-dipyridyl derivative, 2,4′-dipyridyl derivative, and 4,4′-dipyridyl by using a dilute aqueous copper sulfate solution to insolubilize and remove the 2,2′-dipyridyl derivative and 4,4′-dipyridyl are disclosed.
Claims10
A method of producing 2,4′-dipyridyl derivatives having the formula (II):
- 45
- wherein R3 and R4 independently represent a hydrogen atom, a halogen atom, or C1-C4 alkyl group
- comprising reacting 2-halopyridine derivatives having the formula (I):
- 46
- wherein X represents a halogen atom and R3 and R4 are the same as defined above with 4-halopyridine using a nickel complex catalyst in the presence or absence of a halogenated tetraalkylammonium to cause a coupling reaction therebetween.
A method of separating of 2,4′-dipyridyl derivatives comprising the steps of:
- dissolving a mixture of dipyridyl derivative isomers containing a 2,4′-dipyridyl derivative having the formula (II):
- 47
- wherein R3 and R4 independently represents a hydrogen atom, a halogen atom, or a C1-C4 alkyl group
- in an organic solvent;
- and, then,
- applying silica gel column chromatography to the solution obtained above.
A method of separating a 2,4′-dipyridyl derivative comprising the steps of:
- dissolving a mixture of dipyridyl derivative isomers containing a 2,4′-dipyridyl derivative having the formula (II):
- 48
- wherein R3 and R4 independently represent a hydrogen atom, a halogen atom, or a C1-C4 alkyl group
- in an organic solvent;
- and then
- insolubilizing and removing the 2,2′-dipyridyl derivative and 4,4′-dipyridyl as copper sulfate salts.
Dependencies are inferred from the claim text.