Hydrochloric Acid → 6-Chloro-1,3-benzothiazol-2-ol

HRID 223398Notes

Reaction equation

HRID 223398 reaction equation
Cl[C:2]1[S:3][C:4]2[CH:10]=[C:9]([Cl:11])[CH:8]=[CH:7][C:5]=2[N:6]=1.Cl.C([OH:15])C>>[Cl:11][C:9]1[CH:8]=[CH:7][C:5]2[NH:6][C:2](=[O:15])[S:3][C:4]=2[CH:10]=1

Participants

4

Reactant 3

HCID 313Hydrochloric AcidHCID 702EthanolHCID 771762,6-Dichlorobenzothiazole

Product 1

HCID 1884436-Chloro-1,3-benzothiazol-2-ol

Procedure

4.081 gm (0.02 mol) of 2,6-dichloro-benzothiazole were refluxed for 4 hours in 100 ml of a mixture of equal parts of ethanol and concentrated hydrochloric acid. After distilling the reaction mixture with 100 ml of water, the resulting precipitate was filtered off and washed thoroughly with water. For further purification the precipitate was taken up in aqueous 10% sodium hydroxide, the solution was filtered, and the filtrate was extracted twice with 100 ml each of ether. The aqueous phase was acidified with hydrochloric acid, and the resulting precipitate was collected by suction filtration, washed with water and recrystallized once from ethanol and once from toluene, each time in the presence of activated charcoal. 3.1 gm (83% of theory) of crystals with a melting point of 212°-213° C. were obtained. According to mixed melting point determination, elemental analysis, and thin-layer chromatography, the product was identical to the product obtained in Example 6.

Workup

  1. distillationAfter distilling the reaction mixture with 100 ml of water
  2. filtrationthe resulting precipitate was filtered off
  3. washwashed thoroughly with water
  4. customFor further purification the precipitate
  5. filtrationthe solution was filtered
  6. extractionthe filtrate was extracted twice with 100 ml each of ether
  7. filtrationthe resulting precipitate was collected by suction filtration
  8. washwashed with water
  9. customrecrystallized once from ethanol and once from toluene
  10. custom3.1 gm (83% of theory) of crystals with a melting point of 212°-213° C. were obtained
  11. additionto mixed melting point determination, elemental analysis, and thin-layer chromatography

Sources & evidence

ORD record
ord-e69fe2d9261f4cceb4972bd29207955e
Source dataset
uspto-grants-1982_10
Patent number
US04353919

Reaction notes

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