Reaction #2348127

Reaction equation

3-nitro-4-[(E)-2-(4-hydroxyphenyl)-vinyl]phenol

ammonium chloride

→

3-Amino-4-[(E)-2-(4-hydroxy-phenyl)vinyl]phenol

Yield 81.2%

Solvents

acetone

water

Conditions

Workup

1. 1
   TemperatureThe mixture was heated
2. 2
   Temperatureto reflux
3. 3
   Otherthe oil bath was removed
4. 4
   Temperatureto maintain
5. 5
   Othera moderate reaction
6. 6
   workup.ADDITIONwas added
7. 7
   TemperatureThe reaction mixture was then heated
8. 8
   Temperatureto reflux for an additional 2 h
9. 9
   OtherThe precipitate was removed by filtration
10. 10
    Washwashed with acetone (2×20 mL) and with ethyl acetate (2×30 mL)
11. 11
    ConcentrationThe combined washings were concentrated in vacuo
12. 12
    Otherthe crude product was purified by column chromatography

Procedure

To a solution of the product of 3-nitro-4-[(E)-2-(4-hydroxyphenyl)-vinyl]phenol (216 mg, 0.84 mmol) in acetone (6 mL) was added a solution of ammonium chloride (89.9 mg, 1.68 mmol) in 2 mL of water. The mixture was heated to reflux, and the oil bath was removed. Zinc dust (164.8 mg, 2.5 mmol) was added in small portions to the reaction mixture to maintain a moderate reaction. After the reaction subsided an additional portion of zinc (82.4 mg, 1.25 mmol) was added. The reaction mixture was then heated to reflux for an additional 2 h. The precipitate was removed by filtration, washed with acetone (2×20 mL) and with ethyl acetate (2×30 mL). The combined washings were concentrated in vacuo and the crude product was purified by column chromatography using 5% methanol in dichloromethane to afford 3-Amino-4-[(E)-2-(4-hydroxy-phenyl)vinyl]phenol (155 mg, 72%). MS (ES) m/z: 228.11 (M+1), 134.06; 13C-NMR (DMSO-d6): δ 158.3, 156.9, 147.9, 130.4, 130.2, 127.9, 126.9, 124.5, 122.0, 115.9, 115.5, 114.2, 105.4, 102.2. Mp. 229-232° C.

Source