HCID 13745611, compound → 2-Benzothiazolinone, 5-methoxy-

HRID 223388Notes

Reaction equation

HRID 223388 reaction equation
C([N:4]1[C:8]2[CH:9]=[C:10]([O:13][CH3:14])[CH:11]=[CH:12][C:7]=2[S:6][C:5]1=[O:15])(=O)C>Cl.C(O)C>[CH3:14][O:13][C:10]1[CH:11]=[CH:12][C:7]2[S:6][C:5](=[O:15])[NH:4][C:8]=2[CH:9]=1

Participants

4

Reactant 1

HCID 13745611HCID 13745611, compound

Product 1

HCID 271322-Benzothiazolinone, 5-methoxy-

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 702EthanolSolvent

Procedure

7.0 gm (0.0314 mol) of 3-acetyl-5-methoxy-2(3H)-benzothiazolone were suspended in a mixture of 210 ml of 5 N hydrochloric acid and 70 ml of ethanol, and the suspension was refluxed for one hour. The still hot mixture was filtered, diluted with 200 ml of water and brought to a temperature of 5° C. by external cooling with ice. After standing for 2 hours, the precipitate was filtered off, and the dried product was purified chromatographically on silica gel, using 1,2-dichloroethane-acetone (volume ratio 9:1) for elution, and finally recrystallized from methanol and from 1,2-dichloro-ethane, each time in the presence of activated charcoal. The slightly yellow crystals obtained with a yield of 3.25 gm (57% of theory) melted at 168°-170° C.

Workup

  1. temperaturethe suspension was refluxed for one hour
  2. filtrationThe still hot mixture was filtered
  3. additiondiluted with 200 ml of water
  4. custombrought to a temperature of 5° C.
  5. temperatureby external cooling with ice
  6. filtrationthe precipitate was filtered off
  7. customthe dried product was purified chromatographically on silica gel
  8. washfor elution
  9. customfinally recrystallized from methanol and from 1,2-dichloro-ethane
  10. customThe slightly yellow crystals obtained with a yield of 3.25 gm (57% of theory) melted at 168°-170° C.

Sources & evidence

ORD record
ord-d88556525b6b48b0a944500ee95a3b5a
Source dataset
uspto-grants-1982_10
Patent number
US04353919

Reaction notes

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