Hydrochloric Acid → 6-Methoxybenzo[d]isothiazole-3-carboxylic acid

HRID 1867270Notes

Reaction equation

HRID 1867270 reaction equation
[CH3:1][O:2][C:3]1[CH:14]=[CH:13][C:6]2[C:7]([C:10](N)=[O:11])=[N:8][S:9][C:5]=2[CH:4]=1.[OH-:15].[Na+].Cl>CO>[CH3:1][O:2][C:3]1[CH:14]=[CH:13][C:6]2[C:7]([C:10]([OH:15])=[O:11])=[N:8][S:9][C:5]=2[CH:4]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 666364706-Methoxybenzisothiazole-3-carboxamide

Product 1

HCID 666368056-Methoxybenzo[d]isothiazole-3-carboxylic acidYield 89%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of the amide (5.46 mmol) in methanol (100 mL) was added 10 N sodium hydroxide (12 mL). The mixture was heated at reflux for 12 h, cooled to rt, and was acidified to pH <2 by the slow addition of conc. hydrochloric acid. The organic layer was extracted with dichloromethane (2×) and was dried over sodium sulfate. The crude product was purified by chromatography (300/50/1 dichloromethane/methanol/formic acid) to provide 6-methoxy-1,2-benzisothiazole-3-carboxylic acid (89%) as a pink solid. The acid was coupled with 1,4-diazabicyclo[3.2.2]nonane according to procedure A.

Workup

  1. temperatureThe mixture was heated
  2. temperatureat reflux for 12 h
  3. extractionThe organic layer was extracted with dichloromethane (2×)
  4. dry with materialwas dried over sodium sulfate
  5. customThe crude product was purified by chromatography (300/50/1 dichloromethane/methanol/formic acid)

Sources & evidence

ORD record
ord-4c76bb4c441b440da89aff4ea820b665
Source dataset
uspto-grants-2009_12
Patent number
US07632831B2

Reaction notes

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