4-Bromophenylhydrazine hydrochloride → HCID 20289483, compound

5-Chloropentanal (ca. 70% pure, 8.0 g) was added to a suspension of 4-bromophenylhydrazine hydrochloride (13.4 g) in aqueous acetic acid (50%, 300 ml). The mixture was heated rapidly to boiling with vigorous stirring and maintained at reflux for 7 hours. The resulting dark brown solution was cooled to room temperature, diluted with water (300 ml) and extracted with ethyl acetate (4×150 ml). The combined extracts were washed with water (200 ml) and saturated aqueous sodium hydrogen carbonate (4×250 ml), dried (MgSO4), filtered and evaporated to a dark brown oil (14.7 g), which was purified on a silica column (Kieselgel 60, 200 g) eluted with ethyl acetate:light petroleum (b.p. 60°-80°) (1:2) followed by bulb to bulb distillation twice in vacuo to give the title compound as a yellow oil (4 g) b.p. 200° C., 0.5 mm, which rapidly darkened on storage.

1. temperatureThe mixture was heated rapidly
2. temperaturemaintained
3. temperatureat reflux for 7 hours
4. extractionextracted with ethyl acetate (4×150 ml)
5. washThe combined extracts were washed with water (200 ml) and saturated aqueous sodium hydrogen carbonate (4×250 ml)
6. dry with materialdried (MgSO4)
7. filtrationfiltered
8. customevaporated to a dark brown oil (14.7 g), which
9. customwas purified on a silica column (Kieselgel 60, 200 g)
10. washeluted with ethyl acetate
11. distillationlight petroleum (b.p. 60°-80°) (1:2) followed by bulb to bulb distillation twice in vacuo

ORD record

ord-2c17c8c0b0fb4b2daf6edee7182d3a4a

Source dataset

uspto-grants-1981_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04252803