Phosphoric Acid → 5-(4-Methoxyphenyl)-2-(pyridin-4-yl)oxazole

HRID 2164693Notes

Reaction equation

HRID 2164693 reaction equation
[C:1]([NH:9][CH2:10][C:11]([C:13]1[CH:18]=[CH:17][C:16]([O:19][CH3:20])=[CH:15][CH:14]=1)=[O:12])(=O)[C:2]1[CH:7]=[CH:6][N:5]=[CH:4][CH:3]=1.P(=O)(O)(O)O>C(OC(=O)C)(=O)C>[N:5]1[CH:6]=[CH:7][C:2]([C:1]2[O:12][C:11]([C:13]3[CH:18]=[CH:17][C:16]([O:19][CH3:20])=[CH:15][CH:14]=3)=[CH:10][N:9]=2)=[CH:3][CH:4]=1

Participants

4

Reactant 2

HCID 1004Phosphoric AcidHCID 9993270N-[2-(4-Methoxyphenyl)-2-oxoethyl]-4-pyridinecarboxamide

Product 1

HCID 6198395-(4-Methoxyphenyl)-2-(pyridin-4-yl)oxazoleYield 72%

Reagents, catalysts & solvents 1

HCID 7918Acetic AnhydrideSolvent

Conditions

Temperature
40 °C

Procedure

α-isonicotinamido-p-methoxyacetophenone (11.5 g., 0.043 mole) was added portion-wise to a stirred solution of 200 ml of acetic anhydride and 15 ml of 90% phosphoric acid; during the addition an exotherm raised the reaction temperature to 40° C. After the addition was complete the reaction mixture was stirred and refluxed for 2 hours. After cooling, the supernatant liquid was decanted from the viscous precipitate, which was crystallized by titration with 350 ml of 1% aqueous sodium hydroxide. The yellow solid was filtered, washed with distilled water (200 ml), and dried in vacuo yielding 7.76 g. (yield 72%) of 2-(4-pyridyl)-5-p-methoxyphenyloxazole, m.p. 105°-107° C.

Workup

  1. additionduring the addition an exotherm
  2. additionAfter the addition
  3. temperaturerefluxed for 2 hours
  4. temperatureAfter cooling
  5. customthe supernatant liquid was decanted from the viscous precipitate, which
  6. customwas crystallized by titration with 350 ml of 1% aqueous sodium hydroxide
  7. filtrationThe yellow solid was filtered
  8. washwashed with distilled water (200 ml)
  9. customdried in vacuo
  10. customyielding 7.76 g

Sources & evidence

ORD record
ord-4fc68892b1724c43b27925e90af0b4dd
Source dataset
uspto-grants-1985_03
Patent number
US04506368

Reaction notes

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