Triethylamine → 3-Chloro-7-methylbenzo[d]isoxazole

HRID 2051007Notes

Reaction equation

HRID 2051007 reaction equation
O1[C:5]2[CH:6]=[CH:7]C=[CH:9][C:4]=2[C:3]([OH:10])=N1.P(Cl)(Cl)([Cl:13])=O.C([N:18]([CH2:21][CH3:22])CC)C>>[Cl:13][C:21]1[C:22]2[CH:7]=[CH:6][CH:5]=[C:4]([CH3:9])[C:3]=2[O:10][N:18]=1

Participants

4

Reactant 3

HCID 8471TriethylamineHCID 24813Phosphorus oxychlorideHCID 178518983HCID 178518983, compound

Product 1

HCID 150574483-Chloro-7-methylbenzo[d]isoxazoleYield 51.1%

Conditions

Temperature
135 °C

Procedure

To a stirred mixture of 114 parts of 1,2-benzisoxazol-3-ol and 230 parts of phosphoryl chloride were added dropwise 160 parts of N,N-diethylethanamine (exothermic reaction). Upon complete addition, the reaction mixture was stirred overnight at 135° C. The mixture was poured into crushed ice and the product was extracted with trichloromethane. The extract was dried, filtered and evaporated. The residue was boiled in 2,2'-oxybispropane. The solvent was decanted (this was repeated twice) and the residue was purified by column chromatography over silica gel using a mixture of trichloromethane and methanol (97:3 by volume) as eluent. The pure fractions were collected and the eluent was evaporated, yielding 60 parts (51.1%) of 3-chloro-7-methyl-1,2-benzisoxazole as a residue (int. 1).

Workup

  1. additionUpon complete addition
  2. additionThe mixture was poured
  3. custominto crushed ice
  4. extractionthe product was extracted with trichloromethane
  5. customThe extract was dried
  6. filtrationfiltered
  7. customevaporated
  8. customThe solvent was decanted (
  9. customwas purified by column chromatography over silica gel using
  10. additiona mixture of trichloromethane and methanol (97:3 by volume) as eluent
  11. customThe pure fractions were collected
  12. customthe eluent was evaporated

Sources & evidence

ORD record
ord-3a5f189860fc42eeac3bdff0a772886b
Source dataset
uspto-grants-1991_05
Patent number
US05015740

Reaction notes

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