Hydroxyamine hydrochloride → 5-(4-Chlorophenyl)-4-(pyridin-4-yl)isoxazole
Reaction equation
C[N:2](C)[CH:3]=[C:4]([C:14]1[CH:19]=[CH:18][N:17]=[CH:16][CH:15]=1)[C:5]([C:7]1[CH:12]=[CH:11][C:10]([Cl:13])=[CH:9][CH:8]=1)=[O:6].Cl.NO>C(O)C>[Cl:13][C:10]1[CH:11]=[CH:12][C:7]([C:5]2[O:6][N:2]=[CH:3][C:4]=2[C:14]2[CH:19]=[CH:18][N:17]=[CH:16][CH:15]=2)=[CH:8][CH:9]=1Participants
4
Procedure
A solution of 3-dimethylamino-1-(4-chlorophenyl)-2-(pyridin-4-yl)-2-propen-1-one (22.80 g, 79.7 mmol), hydroxylamine hydrochloride (18.01 g, 0.26 mole), and 150 mL ethanol was heated to reflux for 30 minutes. The reaction mixture was then cooled to room temperature and concentrated in vacuo. The residue was dissolved in 1N hydrochloric acid and then treated with an aqueous saturated solution of sodium bicarbonate. The precipitates were collected by filtration, washed with water and ethanol, and dried to yield 5-(4-chlorophenyl)-4-(pyridin-4-yl)isoxazole (20.50 g, 93%). m.p. 120.8-120.9° C. 1H NMR (CDCl3/CD3OD/300 MHz) δ 8.53 (d, 2H), 8.46 (s, 1H), 7.51 (d, 2H), 7.41-7.34 (m, 4H). ESLRMS m/z 257 (M+H). ESHRMS m/z 257.0457 (M+H, C14H2N2OCl requires 257.0482).