Tetrahydrofuran → 5-Chloro-2-(3-chloropyridin-4-yl)-6-(trifluoromethyl)benzoxazole

HRID 1913654Notes

Reaction equation

HRID 1913654 reaction equation
[Cl:1][C:2]1[CH:22]=[N:21][CH:20]=[CH:19][C:3]=1[C:4]([NH:6][C:7]1[CH:12]=[C:11]([Cl:13])[C:10]([C:14]([F:17])([F:16])[F:15])=[CH:9][C:8]=1[OH:18])=O.O1CCCC1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.N(C(OCC)=O)=NC(OCC)=O>C1(C)C=CC=CC=1>[Cl:13][C:11]1[C:10]([C:14]([F:17])([F:16])[F:15])=[CH:9][C:8]2[O:18][C:4]([C:3]3[CH:19]=[CH:20][N:21]=[CH:22][C:2]=3[Cl:1])=[N:6][C:7]=2[CH:12]=1

Participants

6

Reactant 4

HCID 8028TetrahydrofuranHCID 11776Triphenylphosphine2×HCID 220568ethyl N-ethoxycarbonyliminocarbamate2×HCID 668807913-chloro-N-[5-chloro-2-hydroxy-4-trifluoromethylphenyl]isonicotinamide

Product 1

HCID 529199115-Chloro-2-(3-chloropyridin-4-yl)-6-(trifluoromethyl)benzoxazoleYield 58.2%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent2×

Procedure

To a mixture of 0.67 g of 3-chloro-N-[5-chloro-2-hydroxy-4-(trifluoromethyl)phenyl]isonicotinamide, 7 ml of tetrahydrofuran and 0.55 g of triphenylphosphine, 0.91 g of 40% toluene solution of diethyl azodicarboxylate was added dropwise at room temperature. The reaction mixture was stirred for 1.5 hours. To the mixture, 0.14 g of triphenylphosphine and 0.23 g of 40% toluene solution of diethyl azodicarboxylate were added and stirred for further one hour. The reaction mixture was concentrated under reduced pressure. The residue was subjected to silica gel column chromatography, and the resultant crystals were washed with isopropanol and hexane to give 0.37 g of 5-chloro-2-(3-chloropyridin-4-yl)-6-(trifluoromethyl)benzoxazole (hereinafter, referred to as “active compound 79”).

Workup

  1. additionwas added dropwise at room temperature
  2. stirringstirred for further one hour
  3. concentrationThe reaction mixture was concentrated under reduced pressure
  4. washthe resultant crystals were washed with isopropanol and hexane

Sources & evidence

ORD record
ord-7b85f2cabd374ed7be18fea92d13a058
Source dataset
uspto-grants-2013_12
Patent number
US08609705B2

Reaction notes

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