O-tert-butylhydroxylamine hydrochloride → (E)-2-(3-bromo-alpha-t-butoxyimino-4-fluorobenzyl)-3-hydroxypyridine

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-(3-bromo-4-fluorobenzoyl)-3-hydroxypyridine (2.96 g), O-t-butyl hydroxylamine hydrochloride (1.88 g) and acetic acid (50 mL) was stirred at 90° C. for 14 hours. The reaction mixture was concentrated in vacuo, which was subjected to addition with ethyl acetate and water. The ethyl acetate solution was washed with aqueous NaHCO3 and a saturated aqueous saline solution, successively, which was dried (magnesium sulfate), followed by distilling off the solvent under reduced pressure. The residue was subjected to purification by means of a silica gel column (ethyl acetate--hexane) to afford (E)-2-(3-bromo-α-t-butoxyimino-4-fluorobenzyl)-3-hydroxypyridine (1.10 g) and (Z)-2-(3-bromo-α-t-butoxyimino-4-fluorobenzyl)-3-hydroxypyridine (1.97 g) (compounds 17 and 16).

Provenance & Evidence