Sodium Thiosulfate → 2,2-Difluoro-6-[(4,5-dimethoxy-2-pyridinyl)methylsulfinyl]-5H-1,3-dioxolo[4,5-f]benzimidazole

HRID 845523Notes

Reaction equation

HRID 845523 reaction equation
[F:1][C:2]1([F:26])[O:25][C:5]2=[CH:6][C:7]3[NH:11][C:10]([S:12][CH2:13][C:14]4[CH:19]=[C:18]([O:20][CH3:21])[C:17]([O:22][CH3:23])=[CH:16][N:15]=4)=[N:9][C:8]=3[CH:24]=[C:4]2[O:3]1.Cl[O-].[Na+].S([O-])([O-])(=[O:32])=S.[Na+].[Na+]>O1CCOCC1.[OH-].[Na+]>[F:26][C:2]1([F:1])[O:25][C:5]2=[CH:6][C:7]3[NH:11][C:10]([S:12]([CH2:13][C:14]4[CH:19]=[C:18]([O:20][CH3:21])[C:17]([O:22][CH3:23])=[CH:16][N:15]=4)=[O:32])=[N:9][C:8]=3[CH:24]=[C:4]2[O:3]1

Participants

6

Reactant 3

HCID 24477Sodium ThiosulfateHCID 151635072,2-Difluoro-6-[(4,5-dimethoxy-2-pyridyl)methylthio]-5H-[1,3]-dioxolo[4,5-f]benzimidazoleHCID 23665760Sodium Hypochlorite2×

Product 1

HCID 151635102,2-Difluoro-6-[(4,5-dimethoxy-2-pyridinyl)methylsulfinyl]-5H-1,3-dioxolo[4,5-f]benzimidazole

Reagents, catalysts & solvents 2

HCID 14798Sodium HydroxideSolvent2×HCID 312751,4-DioxaneSolvent2×

Conditions

Temperature
0 °C

Procedure

0.76 g of 2,2-difluoro-6-[(4,5-dimethoxy-2-pyridyl)methylthio]-5H-[1,3]-dioxolo[4,5-f]benzimidazole are dissolved in 10 ml of dioxane and 2 ml of 1N sodium hydroxide solution. An equimolar amount of a titrated aqueous sodium hypochlorite solution, to which 1 mole per liter of sodium hydroxide solution has been added, is first added dropwise, while cooling with ice, and after one hour a further equivalent and after 3 hours half the equimolar amount of sodium hypochlorite are added, to achieve complete reaction. After a reaction time of 4 hours, 5 ml of 5% strength sodium thiosulfate solution and another 25 ml of dioxane are added and the upper dioxane phase is separated off, washed once with 5 ml of sodium thiosulfate solution and concentrated on a rotary evaporator. The oily residue is dissolved in 20 ml of water and 10 ml of ethyl acetate and the solution is brought to pH 7 with about 100 ml of a buffer solution of pH 6.8. The solid which has precipitated out is filtered off with suction over a suction filter, washed with water, extracted by stirring at 0° C. with acetone and dried. 0.7 g (87% of theory) of the title compound is obtained in the form of colorless crystals; decomp. at 211°-213° C.

Workup

  1. additionis first added dropwise
  2. temperaturewhile cooling with ice
  3. customreaction
  4. customthe upper dioxane phase is separated off
  5. washwashed once with 5 ml of sodium thiosulfate solution
  6. concentrationconcentrated on a rotary evaporator
  7. dissolutionThe oily residue is dissolved in 20 ml of water
  8. customThe solid which has precipitated out
  9. filtrationis filtered off with suction over a suction
  10. filtrationfilter
  11. washwashed with water
  12. extractionextracted
  13. customdried

Sources & evidence

ORD record
ord-a14b627a6f0a4b39b148a1c930b4fd34
Source dataset
uspto-grants-1988_07
Patent number
US04758579

Reaction notes

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