Methanol → Thiophene-2-sulfonyl bromide

HRID 444598Notes

Reaction equation

HRID 444598 reaction equation
CO.NN.[S:5]1[CH:9]=[CH:8][CH:7]=[C:6]1[S:10](Cl)(=[O:12])=[O:11].[Br:14]Br>C(Cl)(Cl)Cl.O>[S:5]1[CH:9]=[CH:8][CH:7]=[C:6]1[S:10]([Br:14])(=[O:12])=[O:11]

Participants

7

Reactant 4

HCID 887MethanolHCID 9321HydrazineHCID 24408Bromine2×HCID 855182-Thiophenesulfonyl chloride

Product 1

HCID 12874989Thiophene-2-sulfonyl bromideYield 67.5%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6212ChloroformSolvent

Conditions

Temperature
7 °C

Procedure

In a 500 ml Erlenmeyer flask equipped with a magnetic stirrer and a thermometer were placed 200 ml of methanol and 6.80 g (0.20 mol) of 95% hydrazine. This solution wa cooled to 7° C. and 18.26 g (0.10 mol) of 2-thiophenesulfonyl chloride was added portion-wise in such a manner that the temperature did not exceed 15° C. After the addition was complete, the reaction mixture was allowed to warm to room temperature. The methanol was removed in vacuo leaving a mixture of a heavy oil and a fluffy solid. The mixture was treated with water, and the solid dissolved and oil separated. The mixture of oil and water (which contained the hydrazine hydrochloride from the first reaction) was placed in a flask containing 300 ml of chloroform and a magnetic stirrer. Crushed ice was added and to the resulting slurry 64.0 g of bromine was added at such a rate that the reaction temperature remained below 10° C. After the addition was complete and the bromine color had dissipated, the layers were separated. The chloroform layer was dried over anhydrous magnesium sulfate, and the chloroform removed in vacuo leaving a yellow oil which crystallized on addition of hexane. The solid was filtered and dried to give 15.33 g of the title compound as slightly yellow crystals, mp 49°-51° C.

Workup

  1. customIn a 500 ml Erlenmeyer flask equipped with a magnetic stirrer
  2. customdid not exceed 15° C
  3. additionAfter the addition
  4. temperatureto warm to room temperature
  5. customThe methanol was removed in vacuo
  6. customleaving
  7. additiona mixture of a heavy oil
  8. dissolutionthe solid dissolved
  9. customoil separated
  10. additionThe mixture of oil and water (which
  11. customfrom the first reaction)
  12. customwas placed in a flask
  13. additionwas added at such a rate that the reaction temperature
  14. customremained below 10° C
  15. additionAfter the addition
  16. customthe layers were separated
  17. dry with materialThe chloroform layer was dried over anhydrous magnesium sulfate
  18. customthe chloroform removed in vacuo
  19. customleaving a yellow oil which
  20. customcrystallized on addition of hexane
  21. filtrationThe solid was filtered
  22. customdried

Sources & evidence

ORD record
ord-e077fbcb450c4bb09da5efd9423324a6
Source dataset
uspto-grants-1981_04
Patent number
US04264774

Reaction notes

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