Reaction #939050

Reaction equation

Methyl 2-(3-cyano-4-isobutyloxyphenyl)-1,3-benzothiazole-carboxylate

methanol ethanol THF

potassium hydroxide

hydrochloric acid

→

desired compound

Yield 83.0%

2-(3-Cyano-4-isobutyloxyphenyl)-1,3-benzothiazole-7-carboxylic acid

Yield 83.0%

Solvents

water

Conditions

Workup

1. 1
   workup.DISTILLATIONto distill the solvent off
2. 2
   ExtractionThe residue was extracted with chloroform
3. 3
   DryingThe chloroform portion was then dried over anhydrous magnesium sulfate
4. 4
   workup.DISTILLATIONtoo distill the solvent off
5. 5
   OtherThe residual crystalline product was recrystallized from toluene

Procedure

Methyl 2-(3-cyano-4-isobutyloxyphenyl)-1,3-benzothiazole-carboxylate (288 mg, 0.786 mmol) was dissolved in a mixed solvent (50 mL) of methanol/ethanol/THF (2/1/2), and, then a solution of potassium hydroxide (281 mg, 5 mmol) in water (10 mL) was added and stirred for one hour at room temperature. The mixture was made acidic by addition of aqueous 1M hydrochloric acid, and placed under reduced pressure to distill the solvent off. The residue was extracted with chloroform. The chloroform portion was then dried over anhydrous magnesium sulfate and placed under reduced pressure too distill the solvent off. The residual crystalline product was recrystallized from toluene, to give 230 mg (yield 83%) of the desired compound in the form of a white crystalline product.

Source