5-Bromothiophene-2-carbaldehyde → N-[(5-bromothiophen-2-yl)methylidene]hydroxylamine

To a mixture of 2-bromo-5-formylthiophene (2.5 mL, 21 mmol) and pyridine (25 mL) was added hydroxylamine hydrochloride (2.2 g, 32 mmol) on an ice bath, then, the solution was stirred overnight at room temperature. This reaction mixture was concentrated in vacuo, then, partitioned with water (50 mL), ethyl acetate (50 mL) then 1N hydrochloric acid solution (50 mL). The organic layer was separated, sequentially washed with an aqueous solution of saturated sodium bicarbonate and brine, and then, dried over anhydrous magnesium sulfate. The solvent was evaporated in vacuo, the residue was washed with heptane-ethyl acetate (30:1), and the title compound (4.3 g, 21 mmol, 98%) was obtained as a light brown solid.

1. concentrationThis reaction mixture was concentrated in vacuo
2. custompartitioned with water (50 mL), ethyl acetate (50 mL)
3. customThe organic layer was separated
4. washsequentially washed with an aqueous solution of saturated sodium bicarbonate and brine
5. dry with materialdried over anhydrous magnesium sulfate
6. customThe solvent was evaporated in vacuo
7. washthe residue was washed with heptane-ethyl acetate (30:1)

ORD record

ord-91a5ba4b35664c2f99376b0642e63703

Source dataset

uspto-grants-2011_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07932272B2