Reaction #170987

ord-c0ca7f9c36df4ca1b3e249d1f29a7b8c

Conditions

Detailed conditions
See reaction.notes.procedure_details.

Workup

  1. 1
    Otherfor one hour
  2. 2
    OtherDuring HCl gas bubbling the temperature
  3. 3
    Otherrose to 60° C
  4. 4
    OtherThe crude reaction mass
  5. 5
    workup.ADDITIONwas poured onto ice (1 kg)
  6. 6
    Extractionextracted in to ethyl acetate
  7. 7
    Washwashed with water (2×250 ml)
  8. 8
    Dryingdried over sodium sulphate
  9. 9
    workup.DISTILLATIONdistilled
  10. 10
    Otherto get crude 36, which
  11. 11
    Otherwas purified by column chromatography on silica gel
  12. 12
    Otherto get pure 36 (46 g, 78.3) as a light yellow syrup

Procedure

Dry HCl gas was passed through a mixture of 6-(4-nitrophenoxy)-hexanoic acid 35 (50 g, 197.62 mmol) and ethylene glycol (200 ml) was passed dry HCl gas for one hour. During HCl gas bubbling the temperature rose to 60° C. The crude reaction mass was poured onto ice (1 kg), extracted in to ethyl acetate, washed with water (2×250 ml), dried over sodium sulphate and distilled to get crude 36, which was purified by column chromatography on silica gel using benzene as eluant to get pure 36 (46 g, 78.3) as a light yellow syrup.

Source

DOI: 10.6084/m9.figshare.5104873.v1Patent: US08846845B2uspto-grants-2014_09