Thionyl Chloride → 2-Chloro-5-benzoxazolecarbonitrile

HRID 1944697Notes

Reaction equation

HRID 1944697 reaction equation
S=[C:2]1[NH:6][C:5]2[CH:7]=[C:8]([C:11]#[N:12])[CH:9]=[CH:10][C:4]=2[O:3]1.S(Cl)([Cl:15])=O>CN(C=O)C.C(Cl)Cl>[Cl:15][C:2]1[O:3][C:4]2[CH:10]=[CH:9][C:8]([C:11]#[N:12])=[CH:7][C:5]=2[N:6]=1

Participants

5

Reactant 2

HCID 24386Thionyl ChlorideHCID 105114792-Thioxo-2,3-dihydro-1,3-benzoxazole-5-carbonitrile

Product 1

HCID 106311802-Chloro-5-benzoxazolecarbonitrileYield 65%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideCatalystHCID 6344DichloromethaneSolvent

Conditions

Temperature
67.5 °C

Procedure

To a mixture of 2-thioxo-2,3-dihydrobenzooxazole-5-carbonitrile (2.56 g, 14.5 mmol) and thionylchloride (14.1 mL) was added two drops of DMF. The mixture was heated at 65-70° C. for 1 h. Then the mixture was cooled to rt and diluted with CH2Cl2. The solvent and excess thionylchloride were removed under reduced pressure. The residue was purified by column chromatography on silica gel (eluent: 20% EtOAc in Petroleum ether) to give 2-chlorobenzooxazole-5-carbonitrile 1.69 g (65%).

Workup

  1. temperatureThen the mixture was cooled to rt
  2. customThe solvent and excess thionylchloride were removed under reduced pressure
  3. customThe residue was purified by column chromatography on silica gel (eluent: 20% EtOAc in Petroleum ether)

Sources & evidence

ORD record
ord-b9fff86af60947f687d8d4689dc8ae3e
Source dataset
uspto-grants-2013_03
Patent number
US08394842B2

Reaction notes

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