Benzonitrile, m-chloro- → 3-Bromo-5-(3-chlorophenyl)-1,2,4-oxadiazole

HRID 732132

Reaction equation

HRID 732132 reaction equation
[OH:1][N:2]=[C:3]([Br:5])Br.[Cl:6][C:7]1[CH:8]=[C:9]([CH:12]=[CH:13][CH:14]=1)[C:10]#[N:11].C([O-])(O)=O.[Na+]>C1(C)C=CC=CC=1.CC(=O)OCC>[Br:5][C:3]1[N:11]=[C:10]([C:9]2[CH:12]=[CH:13][CH:14]=[C:7]([Cl:6])[CH:8]=2)[O:1][N:2]=1

Participants

6

Reactant 3

HCID 13015Benzonitrile, m-chloro-HCID 516892Sodium BicarbonateHCID 27632191-bromo-N-hydroxymethanecarbonimidoyl bromide

Product 1

HCID 670709033-Bromo-5-(3-chlorophenyl)-1,2,4-oxadiazole

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8857Ethyl AcetateSolvent

Procedure

Hydroxycarbonimidic dibromide (2.21 g, 10.89 mmol) was added portionwise over 1 h 20 min to a mixture of 3-chlorobenzonitrile (3.00 g, 21.29 mmol) and NaHCO3 (2.9 g, 34.87 mmol) in toluene (3 ml) at 90° C. Stirring was continued for 3 h and then the reaction mixture was cooled to r.t., diluted with EA and washed with water. The organic phase was dried and concentrated. A mixture of 3-chlorobenzonitrile and 3-bromo-5-(3-chlorophenyl)-1,2,4-oxadiazole was obtained after flash chromatography (hex/EA 10:1). 1.0 g of the mixture was dissolved in MeNH2 (4 ml, 8.5 M in EtOH) and heated in a microwave reactor for 30 min at 60° C. The volatiles were removed under reduced pressure and the residue was dissolved in water and extracted with CHCl3. The organic phase was dried and concentrated. Recrystallization from EA gave 137 mg of the title compound. 1H NMR: 3.00 (d, 3 H) 4.35 (bs, 1 H) 7.43 (t, 1 H) 7.50-7.55 (m, 1 H) 7.92 (d, 1 H) 8.03 (s, 1 H)

Workup

  1. washwashed with water
  2. customThe organic phase was dried
  3. concentrationconcentrated
  4. additionA mixture of 3-chlorobenzonitrile

Sources & evidence

ORD record
ord-1fcec38ba4fe4e71a2b688ccd8f544c4
Source dataset
uspto-grants-2009_09
Patent number
US07585881B2

Linked notes

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