Formic Acid → 1,3-Benzothiazole-5-carboxylic acid

HRID 408572Notes

Reaction equation

HRID 408572 reaction equation
[SH:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=1[N+:11]([O-])=O.[CH:14](O)=O>[Zn]>[S:1]1[C:2]2[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=2[N:11]=[CH:14]1

Participants

4

Reactant 2

HCID 284Formic AcidHCID 218737794-Mercapto-3-nitrobenzoic acid

Product 1

HCID 27354601,3-Benzothiazole-5-carboxylic acid

Reagents, catalysts & solvents 1

HCID 23994ZincCatalyst

Procedure

A mixture of 4-mercapto-3-nitrobenzoic acid (1 eq.) and zinc dust (0.35 eq) in formic acid was refluxed for 6 h. The mixture was allowed to cool to room temperature, filtered and concentrated under reduced pressure. The residue was diluted with water, adjusted to pH=6.5 with aqueous NaOH (2N) and extracted three times with EtOAc. The organic layers were combined, dried over MgSO4, filtered and concentrated under reduced pressure. The crude was purified by chromatography on silica gel (elution with DCM/MeOH: 1/0 to 95/5) to afford benzothiazole-5-carboxylic acid.

Workup

  1. temperaturewas refluxed for 6 h
  2. filtrationfiltered
  3. concentrationconcentrated under reduced pressure
  4. additionThe residue was diluted with water
  5. extractionextracted three times with EtOAc
  6. dry with materialdried over MgSO4
  7. filtrationfiltered
  8. concentrationconcentrated under reduced pressure
  9. customThe crude was purified by chromatography on silica gel (elution with DCM/MeOH: 1/0 to 95/5)

Sources & evidence

ORD record
ord-35aaba929215457a8b23f729bb0c7ada
Source dataset
uspto-grants-2014_06
Patent number
US08759334B2

Reaction notes

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