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

HRID 2094407Notes

Reaction equation

HRID 2094407 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-36aa616fec8042ebb5922af384d552c2
Source dataset
uspto-grants-2013_05
Patent number
US08445522B2

Reaction notes

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