Acetic Anhydride → 2-(4-Acetoxy-pent-1-yn-1-yl)-benzenesulfonamide

HRID 6382Notes

Reaction equation

HRID 6382 reaction equation
[OH:1][CH:2]([CH3:16])[CH2:3][C:4]#[C:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=1[S:12]([NH2:15])(=[O:14])=[O:13].[C:17](OC(=O)C)(=[O:19])[CH3:18]>N1C=CC=CC=1>[C:17]([O:1][CH:2]([CH3:16])[CH2:3][C:4]#[C:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=1[S:12]([NH2:15])(=[O:13])=[O:14])(=[O:19])[CH3:18]

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 197935762-(4-Hydroxy-pent-1-yn-1-yl)-benzenesulfonamide

Product 1

HCID 197936132-(4-Acetoxy-pent-1-yn-1-yl)-benzenesulfonamide

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

1 g of 2-(4-hydroxy-pent-1-yn-1-yl)-benzenesulfonamide is dissolved in 9 ml of pyridine and cooled to 5°, and 0.44 ml of acetic anhydride is added. The reaction mixture is stirred under argon at 5° for 14 hours and then at room temperature for a further 24 hours. The reaction mixture is then poured onto 100 ml of ice-cold 1N hydrochloric acid and extracted twice with 50 ml of ethyl acetate each time. The combined organic phases are washed twice with 20 ml of 1N hydrochloric acid each time, with 50 ml of water and with 30 ml of saturated sodium chloride solution, dried over magnesium sulfate, filtered off and concentrated by evaporation at 15 torr and 40°. The crude product is chromatographed on 80 g of silica gel (Merck ST 60, 40-63 μm). A 1/1 mixture of hexane and ethyl acetate is used as eluant. 2-(4-Acetoxy-pent- 1-yn-1-yl)-benzenesulfonamide is obtained in the form of a colourless oil. 1H-NMR (200 MHz, DMSO-d6): 7.90 (d, d, 1H); 7.48-7.63 (m, 3H); 7.22 (s, 2H); 5.01 (m, 1H); 2.82 (d, 2H); 2.05 (s, 3H); 1.33 (d, 3H).

Workup

  1. temperaturecooled to 5°
  2. waitat room temperature for a further 24 hours
  3. extractionextracted twice with 50 ml of ethyl acetate each time
  4. washThe combined organic phases are washed twice with 20 ml of 1N hydrochloric acid each time
  5. dry with materialwith 50 ml of water and with 30 ml of saturated sodium chloride solution, dried over magnesium sulfate
  6. filtrationfiltered off
  7. concentrationconcentrated by evaporation at 15 torr and 40°
  8. customThe crude product is chromatographed on 80 g of silica gel (Merck ST 60, 40-63 μm)
  9. additionA 1/1 mixture of hexane and ethyl acetate

Sources & evidence

ORD record
ord-855ec966bfce4a599c81dfe20ff188e7
Source dataset
uspto-grants-1993_09
Patent number
US05248693

Reaction notes

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