1-(4-Bromo-2-nitro-phenoxy)-cyclopropanecarboxylic acid ethyl ester → 6-bromospiro[benzo[b][1,4]oxazine-2,1'-cyclopropan]-3(4H)-one

Temperature

60 °C

To a stirred solution of 1-(4-bromo-2-nitro-phenoxy)-cyclopropanecarboxylic acid ethyl ester (3.5 g, 10.6 mmol) in glacial acetic acid (40 mL) was added iron powder (5.9 g, 106.1 mmol) at room temperature and the reaction mixture was heated at 60° C. for 3 h. The mixture was cooled to room temperature, diluted with ethyl acetate, and filtered through celite bed. The filtrate was concentrated, and the resulting residue was taken in ethyl acetate and washed with water and saturated sodium bicarbonate solution, then the organic layer was dried over sodium sulfate, concentrated and the resulting residue was purified by silica gel column chromatography to furnish 6-bromospiro[4H-1,4-benzoxazine-2,1′-cyclopropane]-3-one (2.51 g).

1. temperatureThe mixture was cooled to room temperature
2. filtrationfiltered through celite bed
3. concentrationThe filtrate was concentrated
4. washwashed with water and saturated sodium bicarbonate solution
5. dry with materialthe organic layer was dried over sodium sulfate
6. concentrationconcentrated
7. customthe resulting residue was purified by silica gel column chromatography

ORD record

ord-e16354d863254b13bbe38b3bea4cb0e0

Source dataset

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08828951B2