Acetic Anhydride → 2-Hydroxy-4-(4-trifluoromethylphenyl)pyridine

HRID 882041Notes

Reaction equation

HRID 882041 reaction equation
[F:1][C:2]([F:17])([F:16])[C:3]1[CH:8]=[CH:7][C:6]([C:9]2[CH:14]=[CH:13][N+:12]([O-])=[CH:11][CH:10]=2)=[CH:5][CH:4]=1.C(OC(=O)C)(=[O:20])C>>[F:1][C:2]([F:17])([F:16])[C:3]1[CH:8]=[CH:7][C:6]([C:9]2[CH:14]=[CH:13][NH:12][C:11](=[O:20])[CH:10]=2)=[CH:5][CH:4]=1

Participants

3

Reactant 2

HCID 7918Acetic AnhydrideHCID 573508294-(4-(Trifluoromethyl)phenyl)pyridine 1-oxide

Product 1

HCID 497584672-Hydroxy-4-(4-trifluoromethylphenyl)pyridineYield 66%

Conditions

Temperature
80 °C

Procedure

4-(4-(Trifluoromethyl)phenyl)pyridine-1-oxide (1.9 g, 7.9 mmol) was heated to 140° C. in acetic anhydride (80 mL) for 5 h. The mixture was concentrated and then heated at 80° C. for 1 h in a mixture of MeOH (20 mL) and aqueous 1 N NaOH (15 mL). The resulting black solution was concentrated to a volume of 15 mL, and the solid was filtered off, rinsed with CH2Cl2 and dried under vacuum to provide the title compound (1.26 g, 66%) as a brown solid: 1H NMR (300 MHz, CD3OD) δ 7.80-7.74 (br m, 5H), 6.85-6.66 (br m, 2H).

Workup

  1. concentrationThe mixture was concentrated
  2. concentrationThe resulting black solution was concentrated to a volume of 15 mL
  3. filtrationthe solid was filtered off
  4. washrinsed with CH2Cl2
  5. customdried under vacuum

Sources & evidence

ORD record
ord-7fd3946c4fe04eaca7676b60ce821573
Source dataset
uspto-grants-2015_03
Patent number
US08993765B2

Reaction notes

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