Process for the preparation of 5-bromo-2 fluorobenzeneboronic acid
AssigneeAmerican Cyanamid Company
InventorKeith D. Barnes
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Abstract
A process is disclosed for the preparation of 5-bromo-2-fluorobenzeneboronic acid, which is useful as an intermediate in the preparation of a non-ester pyrethroid compound. The compound can be, for example, a fluoroolefin, which is useful as a pesticide.
Claims10
A process for the preparation of 5-bromo-2-fluorobenzeneboronic acid which comprises lithiating 1-bromo-4-fluorobenzene with at least about one molar equivalent of a lithium base in the presence of a solvent to form (5-bromo-2-fluorophenyl)lithium, reacting (5-bromo-2-fluorophenyl)lithium with a tri(C.sub.1 -C.sub.6 alkyl) borate to form a di(C.sub.1 -C.sub.6 alkyl) 5-bromo-2-fluorobenzeneboronate, and hydrolyzing the di(C.sub.1 -C.sub.6 alkyl) 5-bromo-2-fluorobenzeneboronate.
A process for the preparation of 5-bromo-2-fluorobenzeneboronic acid which comprises lithiating 1-bromo-4-fluorobenzene with at least about one molar equivalent of a lithium base selected from the group consisting of a lithium dialkylamide and a lithium cyclic amide in the presence of an ether to form (5-bromo-2-fluorophenyl)lithium, reacting (5-bromo-2-fluorophenyl)lithium with a tri(C.sub.1 -C.sub.6 alkyl) borate to form a di(C.sub.1 -C.sub.6 alkyl) 5-bromo-2-fluorobenzeneboronate, and hydrolyzing the di(C.sub.1 -C.sub.6 alkyl) 5-bromo-2-fluorobenzeneboronate with an aqueous organic acid or an aqueous mineral acid.
Dependencies are inferred from the claim text.