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

HRID 884833Notes

Reaction equation

HRID 884833 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-bad515c50c584d44a18c1ce726a93a50
Source dataset
uspto-grants-2012_08
Patent number
US08242133B2

Reaction notes

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