Acetic Anhydride → 4-(4-Chloro-2-methoxyphenyl)pyridin-2(1H)-one

HRID 930750Notes

Reaction equation

HRID 930750 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:13]=[CH:12][N+:11]([O-])=[CH:10][CH:9]=2)=[C:4]([O:15][CH3:16])[CH:3]=1.C(OC(=O)C)(=[O:19])C>>[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:13]=[CH:12][NH:11][C:10](=[O:19])[CH:9]=2)=[C:4]([O:15][CH3:16])[CH:3]=1

Participants

3

Reactant 2

HCID 7918Acetic AnhydrideHCID 579502904-(4-Chloro-2-methoxyphenyl)pyridine 1-oxide

Product 1

HCID 532180124-(4-Chloro-2-methoxyphenyl)pyridin-2(1H)-oneYield 91%

Conditions

Temperature
25 °C

Procedure

4-(4-Chloro-2-methoxyphenyl)pyridine 1-oxide (673 mg, 2.86 mmol) and acetic anhydride (10 mL) were heated at reflux for 3 h. The mixture was concentrated under reduced pressure, and a 1:1 solution of H2O/MeOH (20 mL) was added. The reaction mixture was heated to reflux for 1 h, cooled to 25° C. and concentrated under reduced pressure. The resulting residue was dissolved in hot 2-propanol (3 mL), triturated with Et2O, sonicated for 30 min then placed in the freezer. The solid was filtered off providing the title compound (550 mg, 91%) as a tan solid: 1H NMR (500 MHz, DMSO-d6) δ 11.54 (s, 1H), 7.35-7.33 (m, 2H), 7.01 (s, 1H), 7.08 (d, J=6.6 Hz, 1H), 6.36 (s, 1H), 6.28 (s, 1H), 3.82 (s, 3H); ESI MS m/z 235 [M+H]+.

Workup

  1. temperatureat reflux for 3 h
  2. concentrationThe mixture was concentrated under reduced pressure
  3. additiona 1:1 solution of H2O/MeOH (20 mL) was added
  4. temperatureThe reaction mixture was heated
  5. temperatureto reflux for 1 h
  6. concentrationconcentrated under reduced pressure
  7. dissolutionThe resulting residue was dissolved in hot 2-propanol (3 mL)
  8. customtriturated with Et2O
  9. customsonicated for 30 min
  10. filtrationThe solid was filtered off

Sources & evidence

ORD record
ord-dbd9e5d92b0a4afda396b061acc9df09
Source dataset
uspto-grants-2016_03
Patent number
US09296743B2

Reaction notes

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