Reaction #2006414

Reaction equation

NH4Cl

HCl

40

Methyl-4-(4-aminophenyl)-butanoate

Et3N

LiOH

benzenesulfonyl chloride

→

41

Yield 96.7%

4-[4-(Benzenesulfonylamino)-phenyl]-butyric Acid

Yield 96.7%

Solvents

CH2Cl2

Conditions

Workup

1. 1
   OtherThe phases were separated
2. 2
   Extractionthe organic layer was extracted several times with CH2Cl2
3. 3
   DryingThe combined organic extracts were dried over (MgSO4)
4. 4
   Otherthen evaporated under reduced pressure
5. 5
   workup.DISSOLUTIONThe residue was dissolved in a solvent mixture of THF (25 mL) and water (25 mL)
6. 6
   TemperatureThe mixture was heated at 50° C. for 1 h
7. 7
   OtherThe phases were separated
8. 8
   Extractionthe aqueous layer was extracted several times with AcOEt
9. 9
   DryingThe combined organic extracts were dried over (MgSO4)
10. 10
    Otherthen evaporated
11. 11
    OtherThe crude was purified by flash chromatography

Procedure

To a solution of 40 (500 mg, 2.59 mmol) in CH2Cl2 at room temperature were added Et3N (901 μL, 6.48 mmol) followed by benzenesulfonyl chloride (661 μL, 5.18 mmol). The mixture was stirred overnight at room temperature then treated with a saturated aqueous solution of NH4Cl. The phases were separated and the organic layer was extracted several times with CH2Cl2. The combined organic extracts were dried over (MgSO4) then evaporated under reduced pressure. The residue was dissolved in a solvent mixture of THF (25 mL) and water (25 mL) then LiOH (1.08 g, 25.9 mmol) was added. The mixture was heated at 50° C. for 1 h then treated with HCl (1N) until pH2. The phases were separated and the aqueous layer was extracted several times with AcOEt. The combined organic extracts were dried over (MgSO4) then evaporated. The crude was purified by flash chromatography using CH2Cl2/MeOH (95:5) as solvent mixture yielding 41 (800 mg, 96%) as a white solid

Source