Sulfuric Acid → 6H-Thieno[2,3-b]thiopyran-2-sulfonamide-7,7-dioxide

HRID 653455

Reaction equation

HRID 653455 reaction equation
O[CH:2]1[CH2:7][CH2:6][S:5](=[O:9])(=[O:8])[C:4]2[S:10][C:11]([S:13]([NH2:16])(=[O:15])=[O:14])=[CH:12][C:3]1=2.S(=O)(=O)(O)O>FC(F)(F)C(O)=O>[S:10]1[C:4]2[S:5](=[O:8])(=[O:9])[CH2:6][CH:7]=[CH:2][C:3]=2[CH:12]=[C:11]1[S:13]([NH2:16])(=[O:14])=[O:15]

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 136170125,6-Dihydro-4-hydroxy-4H-thieno[2,3-b]thiopyran-2-sulfonamide 7,7-dioxide

Product 1

HCID 137631516H-Thieno[2,3-b]thiopyran-2-sulfonamide-7,7-dioxideYield 90%

Reagents, catalysts & solvents 1

HCID 6422Trifluoroacetic acidSolvent

Conditions

Temperature
50 °C

Procedure

A mixture of 5,6-dihydro-4-hydroxy-4H-thieno[2,3-b]thiopyran-2-sulfonamide-7,7-dioxide (0.90 g, 0.0031 m), concentrated sulfuric acid (3 ml), and trifluoroacetic acid (20 ml) was stirred and heated at 50° C. for 20.5 hours. After removal of trifluoroacetic acid under reduced pressure, the residue was dissolved in ethyl acetate (25 ml) and the solution was washed with water, twice with saturated sodium bicarbonate solution, twice more with water and dried over sodium sulfate. The solvent was concentrated in vacuo to yield 0.74 g (90%) of crude product. The product was purified by recrystallization from nitromethane after treatment with decolorizing carbon. An analytical sample melted at 214.5°-216° C. (See Example 26).

Workup

  1. customAfter removal of trifluoroacetic acid under reduced pressure
  2. dissolutionthe residue was dissolved in ethyl acetate (25 ml)
  3. washthe solution was washed with water, twice with saturated sodium bicarbonate solution, twice more with water
  4. dry with materialdried over sodium sulfate
  5. concentrationThe solvent was concentrated in vacuo

Sources & evidence

ORD record
ord-3aa79d07ce1b42f2a8f691345ff56674
Source dataset
uspto-grants-1987_06
Patent number
US04677115

Linked notes

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