Lithium Hydroxide → 3,4-Dimethylbenzothiazol-2-one-5-carboxylic acid

HRID 1071908Notes

Reaction equation

HRID 1071908 reaction equation
[CH3:1][N:2]1[C:6]2[C:7]([CH3:15])=[C:8]([C:11]([O:13]C)=[O:12])[CH:9]=[CH:10][C:5]=2[S:4][C:3]1=[O:16].[OH-].[Li+]>O1CCCC1.O>[CH3:1][N:2]1[C:6]2[C:7]([CH3:15])=[C:8]([C:11]([OH:13])=[O:12])[CH:9]=[CH:10][C:5]=2[S:4][C:3]1=[O:16]

Participants

5

Reactant 2

HCID 3939Lithium HydroxideHCID 22390078Methyl 3,4-dimethylbenzothiazol-2-one-5-carboxylate

Product 1

HCID 223900833,4-Dimethylbenzothiazol-2-one-5-carboxylic acidYield 83.7%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

A solution of 10.15 g (43 mmol) of methyl 3,4-dimethylbenzo-thiazol-2-one-5-carboxylate in 100 ml of tetrahydrofuran and 100 ml of water was admixed with 2.06 g (86 mmol) of lithium hydroxide. The solution was then heated at reflux for 2 hours. After cooling, the tetrahydrofuran was removed under reduced pressure, the remaining aqueous solution was acidified and the precipitated solid was filtered off with suction and dried. More product was obtained by extracting the mother liquor with ethyl acetate. This gave a total of 8 g (36 mmol, 83% yield) of 3,4-dimethylbenzothiazol-2-one-5-carboxylic acid of m.p. 235° C.-239° C.

Workup

  1. temperatureThe solution was then heated
  2. temperatureat reflux for 2 hours
  3. temperatureAfter cooling
  4. customthe tetrahydrofuran was removed under reduced pressure
  5. filtrationthe precipitated solid was filtered off with suction
  6. customdried
  7. customMore product was obtained
  8. extractionby extracting the mother liquor with ethyl acetate

Sources & evidence

ORD record
ord-0e5a17ca05fa4c5a8b3ee901968bfa26
Source dataset
uspto-grants-2005_06
Patent number
US06908884B2

Reaction notes

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