反应详情

A mixture of β-(4-fluorophenyl)-α-(2-methyl-1-oxopropyl)-δ-oxobenzenepentanoic acid, ethyl ester (7.92 gm, 20.6 mmol) and hydroxylamine hydrochloride (4.32 gm, 62.2 mmol) in glacial HOAc (100 ml) was refluxed for 2.5 hours. The reaction was cooled to room temperature and poured into an ice cold solution of concentrated NH4OH (140 ml) in H2O (400 ml). The resulting mixture was extracted twice with Et2O and the combined ethereal layers were washed with brine, dried (Na2 SO4), filtered and stripped to yield a gummy orange-red oil. Flash chromatography of the oil (Merck SiO2, 7% EtOAc in hexane) gave 4-(4-fluorophenyl)-2-(1-methylethyl)-6-phenyl-3-pyridinecarboxylic acid, ethyl ester (4.88 gm, 65%) as a near colorless gum.

1. temperaturewas refluxed for 2.5 hours
2. extractionThe resulting mixture was extracted twice with Et2O
3. washthe combined ethereal layers were washed with brine
4. customdried (Na2 SO4)
5. filtrationfiltered
6. customto yield a gummy orange-red oil