(NE,R)-N-[(5-bromo-2-pyridinyl)methylidene]-2-methylpropane-2-sulfinamide → (R)-2-methyl-propane-2-sulfinic acid[(R)-1-(5-bromo-pyridin-2-yl)-ethyl]-amide

HRID 2038781Notes

Reaction equation

HRID 2038781 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5](/[CH:8]=[N:9]/[S@@:10]([C:12]([CH3:15])([CH3:14])[CH3:13])=[O:11])=[N:6][CH:7]=1.[CH3:16][Mg+].[Br-]>C(Cl)Cl>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([C@H:8]([NH:9][S@@:10]([C:12]([CH3:15])([CH3:14])[CH3:13])=[O:11])[CH3:16])=[N:6][CH:7]=1

Participants

4

Conditions

Temperature
-50 °C

Procedure

A solution of (R)-2-methyl-propane-2-sulfinic acid 1-(5-bromo-pyridin-2-yl)-meth-(E)-ylideneamide (6.04 g, 20.9 mmol) in 100 mL of CH2Cl2 was cooled to −50° C. MeMgBr (10.4 mL, 31.3 mmol, 3M in Et2O) was added slowly dropwise via syringe pump over 1 h. The reaction mixture was stirred at −50° C. for 30 min and then quenched by the addition of 100 mL of satd aqueous NH4Cl solution. The mixture was partitioned between 200 mL of CH2Cl2 and 150 mL of water. The organic phase was washed with 150 mL of brine, dried over Na2SO4, and concentrated. The residue was purified by flash chromatography on silica gel, eluting with 50-90% EtOAc in hexanes, to provide 5.38 g (84%) of (R)-2-methyl-propane-2-sulfinic acid[(R)-1-(5-bromo-pyridin-2-yl)-ethyl]-amide as a white solid.

Workup

  1. customquenched by the addition of 100 mL of satd aqueous NH4Cl solution
  2. customThe mixture was partitioned between 200 mL of CH2Cl2 and 150 mL of water
  3. washThe organic phase was washed with 150 mL of brine
  4. dry with materialdried over Na2SO4
  5. concentrationconcentrated
  6. customThe residue was purified by flash chromatography on silica gel
  7. washeluting with 50-90% EtOAc in hexanes

Sources & evidence

ORD record
ord-38250cb3c73140279a4030fe077c2781
Source dataset
uspto-grants-2013_11
Patent number
US08575360B2

Reaction notes

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