4-Fluorobenzenesulfonyl chloride → (R)-2-(4-fluoro-benzenesulfonylamino)-4-methyl-pentanoic acid

HRID 1601101Notes

Reaction equation

HRID 1601101 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([S:8](Cl)(=[O:10])=[O:9])=[CH:4][CH:3]=1.[NH2:12][C@H:13]([CH2:17][CH:18]([CH3:20])[CH3:19])[C:14]([OH:16])=[O:15].C(=O)([O-])[O-].[Na+].[Na+]>O>[F:1][C:2]1[CH:7]=[CH:6][C:5]([S:8]([NH:12][C@H:13]([CH2:17][CH:18]([CH3:20])[CH3:19])[C:14]([OH:16])=[O:15])(=[O:10])=[O:9])=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 95884-Fluorobenzenesulfonyl chlorideHCID 10340Sodium CarbonateHCID 439524D-Leucine

Product 1

HCID 6933578(R)-2-(4-fluoro-benzenesulfonylamino)-4-methyl-pentanoic acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 4-fluoro-benzenesulfonyl chloride (1.65 g, 0.00848 mol), (R)-2-amino-4-methyl-pentanoic acid (1.233 g, 0.009398 mol), and sodium carbonate (1.91 g, 0.0180 mol) in water (15 mL) was stirred at room temperature for 5 days. The solution was filtered, and the filtrate was acidified with concentrated hydrochloric acid to pH=4. The mixture was extracted with ethyl acetate. The extract was washed with saturated sodium chloride, dried (MgSO4), and rotary evaporated to a yellow oil. The oil was chromatographed on silica gel (320 g, 230-400 mesh) eluting with dichloromethane-methanol (10:1, 10×300 mL). Fractions containing product were combined and rotary evaporated to give a pale yellow oil. The oil was dried in vacuo; yield 1.44 g (59%).

Workup

  1. filtrationThe solution was filtered
  2. extractionThe mixture was extracted with ethyl acetate
  3. washThe extract was washed with saturated sodium chloride
  4. dry with materialdried (MgSO4)
  5. customrotary evaporated to a yellow oil
  6. customThe oil was chromatographed on silica gel (320 g, 230-400 mesh)
  7. washeluting with dichloromethane-methanol (10:1, 10×300 mL)
  8. additionFractions containing product
  9. customrotary evaporated
  10. customto give a pale yellow oil
  11. customThe oil was dried in vacuo

Sources & evidence

ORD record
ord-fab245fca2974eb29f75e0e5bcc70d39
Source dataset
uspto-grants-1999_11
Patent number
US05977141

Reaction notes

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