Tetrahydrofuran → 2-(4-Pyridinyl)-5-(trifluoromethoxy)benzoxazole

HRID 2190708Notes

Reaction equation

HRID 2190708 reaction equation
[F:1][C:2]([F:21])([F:20])[O:3][C:4]1[CH:5]=[CH:6][C:7]([OH:19])=[C:8]([NH:10][C:11](=O)[C:12]2[CH:17]=[CH:16][N:15]=[CH:14][CH:13]=2)[CH:9]=1.O1CCCC1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.N(C(OCC)=O)=NC(OCC)=O>O.C1(C)C=CC=CC=1>[N:15]1[CH:16]=[CH:17][C:12]([C:11]2[O:19][C:7]3[CH:6]=[CH:5][C:4]([O:3][C:2]([F:21])([F:20])[F:1])=[CH:9][C:8]=3[N:10]=2)=[CH:13][CH:14]=1

Participants

7

Reactant 4

HCID 8028Tetrahydrofuran2×HCID 11776Triphenylphosphine3×HCID 220568ethyl N-ethoxycarbonyliminocarbamate3×HCID 66880246HCID 66880246, compound

Product 1

HCID 668798542-(4-Pyridinyl)-5-(trifluoromethoxy)benzoxazole

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 1140TolueneSolvent2×

Procedure

To a mixture of 1.96 g of N-[5-(trifluoromethoxy)-2-hydroxyphenyl]isonicotinamide, 35 ml of tetrahydrofuran and 1.73 g of triphenylphosphine, a mixture of 1.26 g of diethyl azodicarboxylate and 5 ml of THF was added dropwise at room temperature. The resultant mixture was stirred at room temperature for two hours. To the mixture, 1.73 g of triphenylphosphine and 3.15 g of 40% toluene solution of diethyl azodicarboxylate were added and stirred for one hour. Furthermore, to the mixture, 0.58 g of triphenylphosphine and 1.05 g of 40% toluene solution of diethyl azodicarboxylate were added and stirred for one hour. The mixture solution was poured into water, followed by extraction with ethyl acetate. The combined organic layers were washed with water and a saturated sodium chloride solution, and dried over magnesium sulfate. The reaction mixture was concentrated. The residue was subjected to silica gel column chromatography to give 2-(pyridin-4-yl)-5-(trifluoromethoxy)benzoxazole (hereinafter, referred to as “active compound 12”).

Workup

  1. additionwas added dropwise at room temperature
  2. stirringstirred for one hour
  3. extractionfollowed by extraction with ethyl acetate
  4. washThe combined organic layers were washed with water
  5. dry with materiala saturated sodium chloride solution, and dried over magnesium sulfate
  6. concentrationThe reaction mixture was concentrated

Sources & evidence

ORD record
ord-00730bcd9433422a97d7921ed737737b
Source dataset
uspto-grants-2012_12
Patent number
US08324387B2

Reaction notes

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