反应详情

温度

0 °C

A solution of sodium nitrite (155 mg, 2.24 mmol) in water (1 mL) was added to a suspension of 3,5-dimethyl-4-(4′-methoxy-3′-iso-propylphenoxy)-aniline (J. Med. Chem. 1995, 38, 695, 640 mg, 2.24 mmol) in ethanol (3 mL) and concentrated hydrochloric acid (12 M, 1.12 mL, 13.44 mmol) at 0° C. The yellow heterogeneous solution slowly turns to an orange clear solution. After stirring at 0° C. for 30 minutes, a solution of tin dichloride (1.53 g, 8.06 mmol) in hydrochloric acid (12 M, 1.3 mL, 15.68 mmol) was added. The orange solution turned green and a white precipitate formed. Ethanol (3 mL) was added to dissolve most of the precipitate and the heterogeneous reaction mixture was stirred at 0° C. After 2 hours, water was added and the precipitate collected by filtration. The sticky solid was dissolved in ethyl acetate and washed with water, 1 N sodium hydroxide then brine. The organics were dried over sodium sulfate, concentrated under reduced pressure and the residue was purified by column chromatography (silica gel, dichloromethane/methanol 95/5 to 90/10) to give 3,5-dimethyl-4-(4′-methoxy-3′-iso-propylphenoxy)-phenyl hydrazine (305 mg, 45%): 1H NMR (300 MHz, CDCl3) δ 6.77 (d, J=3.0 Hz, 1H), 6.67 (d, J=9.0 Hz, 1H) 6.58 (s, 2H), 6.37 (dd, J=9.0, 3.0 Hz, 1H), 3.77 (s, 3H), 3.27 (heptuplet, J=6.9 Hz, 1H), 2.09 (s, 3H), 1.18 (d, J=6.9 Hz, 6H); TLC conditions: Merck silica gel, 250 microns; Mobile phase=dichloromethane-methanol (9:1), Rf=0.6.

1. customa white precipitate formed
2. dissolutionto dissolve most of the precipitate
3. stirringthe heterogeneous reaction mixture was stirred at 0° C
4. waitAfter 2 hours
5. filtrationthe precipitate collected by filtration
6. dissolutionThe sticky solid was dissolved in ethyl acetate
7. washwashed with water, 1 N sodium hydroxide
8. dry with materialThe organics were dried over sodium sulfate
9. concentrationconcentrated under reduced pressure
10. customthe residue was purified by column chromatography (silica gel, dichloromethane/methanol 95/5 to 90/10)