Tributylborane → 4-[2(4-Fluorophenyl)-4,4-dimethylcyclopenten-1-yl)benzenesulfonamide

HRID 1901105Notes

Reaction equation

HRID 1901105 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH2:12][C:11]([CH3:14])([CH3:13])[CH2:10][C:9]=2[C:15]2[CH:20]=[CH:19][C:18]([S:21](C)(=[O:23])=[O:22])=[CH:17][CH:16]=2)=[CH:4][CH:3]=1.C(B(CCCC)CCCC)CCC.C([O-])(=O)C.[Na+].O[NH:44]S(O)(=O)=O>C1COCC1.C([Li])CCC.O>[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH2:12][C:11]([CH3:14])([CH3:13])[CH2:10][C:9]=2[C:15]2[CH:20]=[CH:19][C:18]([S:21]([NH2:44])(=[O:23])=[O:22])=[CH:17][CH:16]=2)=[CH:4][CH:3]=1

Participants

8

Reactant 4

HCID 31216TributylboraneHCID 170246Hydroxysulfamic acidHCID 517045Sodium AcetateHCID 98410791-[2-(4-Fluorophenyl)-4,4-dimethyl-1-cyclopentenyl]-4-methylsulfonylbenzene

Product 1

HCID 102690884-[2(4-Fluorophenyl)-4,4-dimethylcyclopenten-1-yl)benzenesulfonamideYield 43.9%

Reagents, catalysts & solvents 3

HCID 178418339ButyllithiumCatalystHCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

Under nitrogen, a solution of 4.55 g (13.2 mmol) of 1-[2-(4-fluoro phenyl)-4,4-dimethylcyclopenten-1-yl]-4-(methylsulfonyl)benzene (from Step 10 of Example 1) in 50 mL of THF at -78° C. was treated with 6.3 mL (0.27 mmol) of n-butyllithium (2.5M in hexane) over a period of 5 minutes. The reaction was stirred at ambient temperature for 25 minutes, cooled to -78° C., and treated with 19.8 mL (19.8 mmol ) of tributylborane (1.0M in THF). The resulting dark brown solution was stirred at ambient temperature for 30 minutes and then at reflux for 14 hours prior to the addition of 8.7 g (106 mmol) of sodium acetate, 37 mL of water, and 5.2 g (46 mmol) of hydroxyamine-O-sulfonic acid. The resulting light orange mixture was stirred at ambient temperature for 6 hours and the aqueous phase extracted with ethyl acetate. The combined extracts were washed with water, brine, dried (MgSO4), and concentrated in vacuo. The residue was chromatographed on silica gel to give 2.0 g (40%) of 4-[2(4-fluorophenyl)-4,4-dimethylcyclopenten-1-yl)benzenesulfonamide as a colorless solid: mp 117°-118° C.; NMR (CDCl3) δ1.24 (s, 6H), 2.70 (s, 4H), 4.72 (s, 2H), 6.92 (t, J=9 Hz, 2H), 7.09 (dd, J=9 and 7 Hz, 2H), 7.26 (d, J=8 Hz, 2H), 7.74 (d, J=9 Hz, 2H). HRMS. Calc'd for C19H20FNO2S: 345.1199. Found: 345.1194. Anal. Calc'd for [C19H20FNO2S+0.27 H2O]: C, 65.14; H, 5.91; N, 4.00; S, 9.11. Found: C, 65.07; H, 5.94; N, 3.86; S, 9.29.

Workup

  1. temperaturecooled to -78° C.
  2. stirringThe resulting dark brown solution was stirred at ambient temperature for 30 minutes
  3. temperatureat reflux for 14 hours
  4. stirringThe resulting light orange mixture was stirred at ambient temperature for 6 hours
  5. extractionthe aqueous phase extracted with ethyl acetate
  6. washThe combined extracts were washed with water, brine
  7. dry with materialdried (MgSO4)
  8. concentrationconcentrated in vacuo
  9. customThe residue was chromatographed on silica gel

Sources & evidence

ORD record
ord-dcde1b72b33b469e8079b2fa89e2a8d1
Source dataset
uspto-grants-1996_11
Patent number
US05576339

Reaction notes

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