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

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-Eintrag

ord-d240245aa72140a3bb92cfd635069b9c

Quelldatensatz

uspto-grants-2013_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08466114B2