Phosphorus oxide (P4O10) → 2-(2-Chloro-5-nitrophenyl)oxazole

HRID 1910771Notes

Reaction equation

HRID 1910771 reaction equation
O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O.[Cl:15][C:16]1[CH:30]=[CH:29][C:28]([N+:31]([O-:33])=[O:32])=[CH:27][C:17]=1[C:18]([NH:20][CH2:21][CH:22]([O:25]C)OC)=O>CS(O)(=O)=O>[Cl:15][C:16]1[CH:30]=[CH:29][C:28]([N+:31]([O-:33])=[O:32])=[CH:27][C:17]=1[C:18]1[O:25][CH:22]=[CH:21][N:20]=1

Participants

4

Reactant 2

HCID 14812Phosphorus oxide (P4O10)HCID 612487142-chloro-N-(2,2-dimethoxy-ethyl)-5-nitro-benzamide

Product 1

HCID 190776092-(2-Chloro-5-nitrophenyl)oxazoleYield 94.2%

Reagents, catalysts & solvents 1

HCID 6395Methanesulfonic AcidSolvent

Conditions

Temperature
142.5 °C

Procedure

Under nitrogen, phosphorus pentoxide (0.98 g, 6.90 mmol) was added portionwise to a slurry of 2-chloro-N-(2,2-dimethoxy-ethyl)-5-nitro-benzamide (0.5 g, 1.73 mmol) in methanesulfonic acid (5 mL) at r.t. The mixture was heated to 140-145° C. for 6 h. After cooling to r.t., the mixture was poured onto ice-water and extracted with ethyl acetate. The combined organic phases were washed with water then brine, dried over sodium sulfate, filtered and concentrated in vacuo. Further drying under high vacuum gave 2-(2-chloro-5-nitrophenyl)-oxazole (0.366 g, 94%) as a solid.

Workup

  1. temperatureAfter cooling to r.t.
  2. additionthe mixture was poured onto ice-water
  3. extractionextracted with ethyl acetate
  4. washThe combined organic phases were washed with water
  5. dry with materialbrine, dried over sodium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customFurther drying under high vacuum

Sources & evidence

ORD record
ord-f46591ba5e434ca1b400b77a4edb6f2c
Source dataset
uspto-grants-2013_12
Patent number
US08604029B2

Reaction notes

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