Pyridine → HCID 73455955, compound

Participants

Reaction Steps

15 g (41.8 mmol) of 2,2,2-trifluoro-1-(4-dodecyloxyphenyl)-ethanone are dissolved in 100 ml of ethanol. To the solution are added 3.5 g (50.2 mmol) of hydroxylammonium chloride and 10.1 ml (125.4 mmol) of pyridine. The reaction mixture is refluxed for two hours, and the solvent is distilled off by a rotary evaporator. The residue is poured into 100 ml of water, and extracted with 100 ml and then with 50 ml of ethyl acetate. The organic phase is washed with potassium hydrogen sulfate aqueous solution, water, and brine, dried over MgSO4, and concentrated. The residue is dissolved in 100 ml of methylene chloride. To the solution is added 4.2 g of conc. HCl. The reaction mixture is stirred at room temperature overnight, and poured into water. After the aqueous phase is removed, the organic phase is washed with water and brine, dried over MgSO4, and concentrated. The residue is purified by recrystallization from hexane, yielding 9.7 g of 2,2,2-trifluoro-1-(4-dodecyloxyphenyl)-ethanone oxime as a white solid with a melting point of 75-76° C. The structure is confirmed by the 1H-NMR spectrum (CDCl3). δ [ppm]: 0.89(t, 3H), 1.21-1.40 (m, 16H), 1.40-1.52 (m, 2H), 1.80 (m, 2H), 3.99 (t, 2H), 6.97 (d, 2H), 7.53 (d, 2H), 8.43 (s, 1H). The spectrum indicates that the compound is a single isomer, which is tentatively assigned as Z-conformation. When sulfuric acid is used in place of HCl, 2,2,2-trifluoro-1-(4-dodecyloxyphenyl)-ethanone oxime of the single isomer is also obtained.

Provenance & Evidence