Reaction #992723

ord-f36be9597caa4ecda1ae13734173d8ec

Solvents

Conditions

Detailed conditions
See reaction.notes.procedure_details.

Workup

  1. 1
    Temperaturewas heated
  2. 2
    Temperatureat reflux for 2 h under nitrogen
  3. 3
    Otherone peak of the intermediate (RT=5.37)
  4. 4
    Othercan be isolated
  5. 5
    Temperatureheated at 55° C. for 24 h
  6. 6
    OtherThe solvent was evaporated
  7. 7
    Otherthe residue partitioned between AcOEt ethyl acetate and acidic water (pH=3)
  8. 8
    OtherThe crude material was purified by column chromatography (ethyl acetateAcOEt/CH2Cl2/pPetroleum ether, 1:1:1)
  9. 9
    OtherThe residue was crystallized in diethyl ether
  10. 10
    Filtrationfiltered
  11. 11
    Otherto give the target compound
  12. 12
    OtherThis material was triturated in 3 mL of water
  13. 13
    Filtrationfiltered
  14. 14
    Washwashed with water
  15. 15
    Otherdried overnight with the high vacuum pump

Procedure

A mixture of 29 (91 mg, 0.14 mmol) and 1,1′-carbonyldiimidazole (CDI) (47 mg, 0.29 mmol) in dry THF (7 mL) was heated at reflux for 2 h under nitrogen. LCMS analysis shows one peak of the intermediate (RT=5.37). Optionally, the azalactone derivative, if desired, can be isolated. The reaction mixture was cooled to room temperature and cyclopropylsulfonamide (52 mg, 0.43 mmol) was added. Then, DBU (50 μL, 0.33 mmol) was added and the reaction mixture was stirred at room temperature for 1 h, and then heated at 55° C. for 24 h. The solvent was evaporated, and the residue partitioned between AcOEt ethyl acetate and acidic water (pH=3). The crude material was purified by column chromatography (ethyl acetateAcOEt/CH2Cl2/pPetroleum ether, 1:1:1). The residue was crystallized in diethyl ether, filtered to give the target compound contaminated with the cyclopropylsulfonamide. This material was triturated in 3 mL of water, filtered, washed with water and dried overnight with the high vacuum pump to give 60 mg (57%) of the target compound 30 as a slightly yellow powder: m/z=734 (M+H)+, 1H-NMR (CDCl3): 10.94 (s, 1H), 8.08 (d, J=8.6 Hz, 1H), 8.00 (s, 1H), 7.12-7.15 (m, 2H), 6.91 (s, 1H), 6.35 (s, 1H), 5.74-5.77 (m, 1H), 5.63-5.69 (m, 1H), 5.06 (t, J=10.4 Hz, 1H), 4.60 (t, J=12.3 Hz, 1H), 3.93 (s, 3H), 3.35-3.42 (m, 2H), 3.04 (s, 3H), 2.89-2.96 (m, 2H), 2.52-2.52 (m, 2H), 2.37-2.45 (m, 2H), 2.10-2.32 (m, 2H), 1.61-1.93 (m, 4H), 1.3-1.51 (m, 4H), 0.90-1.30 (m, 8H).

Source

DOI: 10.6084/m9.figshare.5104873.v1Patent: US08012939B2uspto-grants-2011_09