Picolyl chloride hydrochloride → 2-(Pyridin-2-yl)-1,3-benzoxazol-6-ol

HRID 366444Notes

Reaction equation

HRID 366444 reaction equation
Cl.[NH2:2][C:3]1[CH:9]=[CH:8][C:6]([OH:7])=[CH:5][C:4]=1[OH:10].Cl.[N:12]1[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=1[CH2:18]Cl.C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1>C(N(CC)CC)C>[N:12]1[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=1[C:18]1[O:10][C:4]2[CH:5]=[C:6]([OH:7])[CH:8]=[CH:9][C:3]=2[N:2]=1

Participants

5

Reactant 3

HCID 23392Picolyl chloride hydrochlorideHCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)HCID 134088224-Aminobenzene-1,3-diol hydrochloride

Product 1

HCID 1357979192-(Pyridin-2-yl)-1,3-benzoxazol-6-ol

Reagents, catalysts & solvents 1

HCID 8471TriethylamineSolvent

Procedure

4-Aminoresorcinol hydrochloride (2.0 g, 12.4 mL), picolinyl chloride hydrochloride (2.4 g, 13.6 mM), triethylamine (2.8 g, 27.2 mM) and pyridinium-p-toluenesulfonate (PPTS, 800 mg, 3.2 mM) were refluxed in xylenes (50 mL) for about 72 hours. The reaction mixture was concentrated and the residue dissolved in ethyl acetate (200 mL) and washed with H2O (3×150 mL). The combined aqueous layer was back extracted with ethyl acetate (200 mL) and the combined organic layer was dried over MgSO4. Filtration and concentration provided 1.0 g. Filtration through a silica gel column eluted with 4% methanol/methylene chloride provided an orange solid, 0.32 g; m.p., 100-103° C.

Workup

  1. concentrationThe reaction mixture was concentrated
  2. dissolutionthe residue dissolved in ethyl acetate (200 mL)
  3. washwashed with H2O (3×150 mL)
  4. extractionThe combined aqueous layer was back extracted with ethyl acetate (200 mL)
  5. dry with materialthe combined organic layer was dried over MgSO4
  6. filtrationFiltration and concentration
  7. customprovided 1.0 g
  8. filtrationFiltration through a silica gel column
  9. washeluted with 4% methanol/methylene chloride
  10. customprovided an orange solid, 0.32 g
  11. customm.p., 100-103° C.

Sources & evidence

ORD record
ord-7d4f07e27f28499daf81c73e69343d96
Source dataset
uspto-grants-2000_10
Patent number
US06130217

Reaction notes

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