p-Bromoacetophenone → (4-Bromo-phenyl)-oxo-acetaldehyde oxime

19.9 g of 4-bromoacetophenone are placed in 150 ml of methanol under nitrogen, and 14.7 ml of isopentyl nitrite are added. To the resulting solution there are then added dropwise, at 17-23° C., 22.2 ml of a 5.4M solution of sodium methanolate in methanol. After 70 hours' stirring at room temperature the orange suspension is concentrated using a rotary evaporator. 300 ml of water are added to the residue, and the mixture is rendered acidic with 60 ml of 2N hydrochloric acid. The resulting yellow suspension is filtered and washed with water; the filter cake is taken up in ethyl acetate and washed with water. The organic phase is washed with saturated sodium chloride solution, dried over sodium sulfate, filtered and concentrated. The crude product is recrystallised from ethyl acetate/toluene. In this way (4-bromophenyl)-oxoacetaldehyde oxime is obtained in the form of a colourless powder.

1. additionTo the resulting solution there are then added dropwise, at 17-23° C.
2. concentrationis concentrated
3. customa rotary evaporator
4. addition300 ml of water are added to the residue
5. filtrationThe resulting yellow suspension is filtered
6. washwashed with water
7. washwashed with water
8. washThe organic phase is washed with saturated sodium chloride solution
9. dry with materialdried over sodium sulfate
10. filtrationfiltered
11. concentrationconcentrated
12. customThe crude product is recrystallised from ethyl acetate/toluene

ORD record

ord-97005d38dc044ddaba68fed24463647f

Source dataset

uspto-grants-2004_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06723720B2