Reaction #1536

Reaction equation

N-t-butyl-3-(chloroacetyl)-2-thiophenesulfonamide

N-t-butyl-3-chloroacetyl-2-thiophenesulfonamide

acetic acid

sodium cyanoborohydride

→

title compound

Yield 84.0%

N-t-butyl-3-(1-acetoxy-2-chloroethyl)-2-thiophenesulfonamide

Yield 84.0%

Solvents

tetrahydrofuran

Conditions

Workup

1. 1
   Othersubjected to a vacuum evaporator
2. 2
   Otherto remove the solvent
3. 3
   workup.ADDITIONTo the residue was added 10 ml of water
4. 4
   Extractionthe resulting solution was extracted with methylene chloride
5. 5
   DryingThe extract was dried over anhydrous magnesium sulfate
6. 6
   Filtrationfiltered
7. 7
   workup.ADDITIONTo the filtrate were added acetic anhydride, pyridine and N,N-dimethylaminopyridine
8. 8
   workup.STIRRINGthe mixture was stirred at normal temperature for 24 hours
9. 9
   Washwashed with 5% aqueous hydrochloric acid solution
10. 10
    OtherThe organic layer was separated
11. 11
    Dryingdried over anhydrous magnesium sulfate
12. 12
    Filtrationfiltered
13. 13
    ConcentrationThe filtrate was concentrated

Procedure

1.5 g (0.005 mole) of N-t-butyl-3-(chloroacetyl)-2-thiophenesulfonamide synthesized in Example 6 was dissolved in the combined solution of 1 ml of acetic acid and 10 ml of tetrahydrofuran and then 0.31 g (0.005 mole) of sodium cyanoborohydride was added slowly thereto. The reaction solution was stirred at normal temperature for 30 minutes and then subjected to a vacuum evaporator to remove the solvent. To the residue was added 10 ml of water and then the resulting solution was extracted with methylene chloride. The extract was dried over anhydrous magnesium sulfate and filtered. To the filtrate were added acetic anhydride, pyridine and N,N-dimethylaminopyridine and the mixture was stirred at normal temperature for 24 hours and then washed with 5% aqueous hydrochloric acid solution. The organic layer was separated, dried over anhydrous magnesium sulfate and filtered. The filtrate was concentrated and the residue was subjected to column chromatography on silica gel to obtain 5 g (Yield: 84%) of the title compound. 1H NMR(CDCl3, δ): 1.3(s, 9H), 2.15(s, 3H), 3.57-3.9(m, 2H), 5.23(s, 1H), 6.5(m, 1H), 7.13(d, 1H), 7.5 (d, 1H)

Source