Dimethylformamide → 2-Chloro-5-nitrobenzo[d]oxazole

HRID 512450Notes

Reaction equation

HRID 512450 reaction equation
S[C:2]1[O:3][C:4]2[CH:10]=[CH:9][C:8]([N+:11]([O-:13])=[O:12])=[CH:7][C:5]=2[N:6]=1.CN(C=O)C.S(Cl)([Cl:21])=O>>[Cl:21][C:2]1[O:3][C:4]2[CH:10]=[CH:9][C:8]([N+:11]([O-:13])=[O:12])=[CH:7][C:5]=2[N:6]=1

Participants

4

Reactant 3

HCID 6228DimethylformamideHCID 24386Thionyl ChlorideHCID 178526504HCID 178526504, compound

Product 1

HCID 103527232-Chloro-5-nitrobenzo[d]oxazole

Conditions

Temperature
65 °C

Procedure

Subsequently, the crude 2-mercapto-5-nitrobenzoxazole (10 g, 51 mmol), previously prepared, was dissolved in thionyl chloride (100 mL). DMF (60 μL) was added and the reaction mixture was heated at 65° C. for 45 min. After cooling, the solvent was removed under reduced pressure and to the residue, toluene was added twice (2×20 mL) and each time subsequently evaporated in vacuo to remove volatiles via azeotrope. The resultant crude product was dissolved in ethyl acetate (400 mL), washed with brine (200 mL), dried over Na2SO4, filtered, and concentrated to give compound 29, 2-chloro-5-nitrobenzoxazole, as (8.2 g, crude).

Workup

  1. temperatureAfter cooling
  2. customthe solvent was removed under reduced pressure and to the residue, toluene
  3. additionwas added twice (2×20 mL)
  4. customeach time subsequently evaporated in vacuo
  5. customto remove volatiles via azeotrope
  6. dissolutionThe resultant crude product was dissolved in ethyl acetate (400 mL)
  7. washwashed with brine (200 mL)
  8. dry with materialdried over Na2SO4
  9. filtrationfiltered
  10. concentrationconcentrated

Sources & evidence

ORD record
ord-a8933e70a14844059ac74a47cc63921b
Source dataset
uspto-grants-2015_08
Patent number
US09102636B2

Reaction notes

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