Acetaldehyde → 1-(4-(Trifluoromethoxy)phenyl)ethan-1-one

A solution of 4-(trifluoromethoxy)iodobenzene (8.64 g.) in anhydrous diethyl ether (60 ml.) was added dropwise at -65° C. to n-butyl-lithium (21 ml. of a 1.6M solution in hexane) over 20 minutes. After stirring for a further 20 minutes, a solution of acetaldehyde (1.6 g.) in diethyl ether (15 ml.) was added, keeping the temperature below -60° C. Stirring was continued for 1 hour, after which time the temperature was allowed to rise to -30° C. and a mixture of glacial acetic acid (15 ml) and diethyl ether (20 ml.) was added. On reaching room temperature, the solution was poured into water, the organic layer was separated, washed with water and then sodium bicarbonate solution, dried over sodium sulphate and filtered, and the solvents were evaporated to give a pale yellow oil which was purified by column chromatography on silica and using chloroform, then chloroform/ethyl acetate (7:3 v/v) as eluent. Evaporation of the appropriate fractions gave a colourless oil which was dissolved in methylene dichloride (60 ml.) and treated with pyridinium chlorochromate (7.35 g.). After stirring for 3 hours, the reaction mixture was diluted with diethyl ether (100 ml.), and the suspension was filtered through a "Florosil" (trade mark) silica pad. Evaporation of the solvent gave 4-trifluoromethoxyacetophenone as a pale yellow oil. N.m.r. in deuteriochloroform gave signals at 2.59 (3H, singlet) and 7.7 (4H, quartet).

1. customthe temperature below -60° C
2. stirringStirring
3. waitwas continued for 1 hour
4. customto rise to -30° C.
5. additionwas added
6. customOn reaching room temperature
7. customthe organic layer was separated
8. washwashed with water
9. dry with materialsodium bicarbonate solution, dried over sodium sulphate
10. filtrationfiltered
11. customthe solvents were evaporated
12. customto give a pale yellow oil which
13. customwas purified by column chromatography on silica
14. customEvaporation of the appropriate fractions
15. customgave a colourless oil which
16. stirringAfter stirring for 3 hours
17. filtrationthe suspension was filtered through a "Florosil" (trade mark) silica pad
18. customEvaporation of the solvent

ORD record

ord-894693d8a5ab45aab32ef939ea28b731

Source dataset

uspto-grants-1990_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04925863