Phosphorus oxychloride → Imidazo[5,1-b]oxazole, 2-phenyl-

HRID 648458Notes

Reaction equation

HRID 648458 reaction equation
[C:1]1([C:7]2[O:11][C:10]([CH2:12][NH:13][CH:14]=O)=[N:9][CH:8]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.P(Cl)(Cl)(Cl)=O>C1(C)C=CC=CC=1>[C:1]1([C:7]2[O:11][C:10]3=[CH:12][N:13]=[CH:14][N:9]3[CH:8]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 20144947HCID 20144947, compound

Product 1

HCID 14098301Imidazo[5,1-b]oxazole, 2-phenyl-

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To 0.6 g (3 mmol) (2) in 15 ml toluene was added dropwise 1 ml phosphorus oxychloride and the resulting solution was heated at 90° overnight. Then, the solvent was removed in vacuo and the residue carefully diluted with 50 ml water. This solution was made basic with 40% NaOH solution and extracted with 4×50 ml portions of methylenechloride. The combined organic extracts were washed with brine, dried and the solvent removed in vacuo to give a dark gum. This was purified by chromatography on silica gel eluting with methylene chloride (97%)-isopropanol (3%) to give pure (3) as a waxy, tan solid, m.p. 128°-131° (dec).

Workup

  1. temperaturethe resulting solution was heated at 90° overnight
  2. customThen, the solvent was removed in vacuo
  3. additionthe residue carefully diluted with 50 ml water
  4. extractionextracted with 4×50 ml portions of methylenechloride
  5. washThe combined organic extracts were washed with brine
  6. customdried
  7. customthe solvent removed in vacuo
  8. customto give a dark gum
  9. customThis was purified by chromatography on silica gel eluting with methylene chloride (97%)-isopropanol (3%)

Sources & evidence

ORD record
ord-a674b0e26bf24eada3f568fbe0017c12
Source dataset
uspto-grants-1988_04
Patent number
US04735956

Reaction notes

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