Sodium Hydroxide → 2-(But-3-ynyl)-5-phenyloxazole

HRID 334564Notes

Reaction equation

HRID 334564 reaction equation
O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O.O=[C:16]([C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=1)[CH2:17][NH:18][C:19](=[O:24])[CH2:20][CH2:21][C:22]#[CH:23].[OH-].[Na+]>O=P(Cl)(Cl)Cl>[CH2:20]([C:19]1[O:24][C:16]([C:25]2[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=2)=[CH:17][N:18]=1)[CH2:21][C:22]#[CH:23]

Participants

5

Reactant 3

HCID 14798Sodium Hydroxide2×HCID 14812Phosphorus oxide (P4O10)HCID 86086916Pent-4-ynoic acid (2-oxo-2-phenyl-ethyl)-amide

Product 1

HCID 860869172-(But-3-ynyl)-5-phenyloxazoleYield 21.6%

Reagents, catalysts & solvents 1

HCID 24813Phosphorus oxychlorideSolvent

Conditions

Temperature
105 °C

Procedure

907 mg (6.39 mmol) of P2O5 were added to a solution of pent-4-ynoic acid (2-oxo-2-phenyl-ethyl)-amide (160 mg, 0.74 mmol) in POCl3 (10.4 mL). The reaction mixture was stirred for 2 hours at 105° C. and then poured carefully onto ice. The solution was basified with NaOH 1N followed by NaOH pellets till pH=8. The aqueous phase was extracted thrice with DCM. The organic phase was washed with brine, dried over MgSO4, filtered and evaporated. The crude residue was purified by flash chromatography (DCM/MeOH 99:1) to yield 31 mg (0.16 mmol, 21%) of 2-(but-3-ynyl)-5-phenyloxazole as an orange oil.

Workup

  1. additionpoured carefully onto ice
  2. extractionThe aqueous phase was extracted thrice with DCM
  3. washThe organic phase was washed with brine
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. customevaporated
  7. customThe crude residue was purified by flash chromatography (DCM/MeOH 99:1)

Sources & evidence

ORD record
ord-196d29d774364504a53a1fb9c5dbb198
Source dataset
uspto-grants-2014_11
Patent number
US08883826B2

Reaction notes

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