4-Chloro-3-nitrobenzoic acid → 2-Methyl-1,3-benzothiazole-5-carboxylic acid

HRID 1498958Notes

Reaction equation

HRID 1498958 reaction equation
Cl[C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=1[N+:11]([O-])=O.O.O.O.O.O.O.O.O.O.[S-2:23].[Na+].[Na+].C(O[C:30](=O)[CH3:31])(=O)C>C(OCC)(=O)C.O.C(O)(=O)C>[CH3:31][C:30]1[S:23][C:2]2[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=2[N:11]=1

Participants

7

Reactant 3

HCID 73204-Chloro-3-nitrobenzoic acidHCID 7918Acetic AnhydrideHCID 73972Sodium sulfide nonahydrate

Product 1

HCID 6499532-Methyl-1,3-benzothiazole-5-carboxylic acidYield 80%

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 962WaterSolvent2×HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
100 °C

Procedure

4-Chloro-3-nitrobenzoic acid (2.02 g, 10.00 mmol), sodium sulfide nonahydrate (7.22 g, 30.00 mmol) and water (5 ml) were suspended, and the mixture was heated at about 100° C. for 30 minutes. After being allowed to cool, the mixture was cooled by ice, and acetic anhydride (18 ml) and acetic acid (10 ml) were added to the mixture. The resulting mixture was heated under reflux for 2 hours and stirred at a room temperature for 15 hours. To the mixture, tap water and then ethyl acetate were added, and sulfur was removed by filtration. The ethyl acetate layer was washed with a saturated saline solution, and then dried over anhydrous magnesium sulfate and concentrated to give the title compound (1.54 g, 80%) as a light-yellow powder.

Workup

  1. temperatureto cool
  2. additionwere added to the mixture
  3. temperatureThe resulting mixture was heated
  4. temperatureunder reflux for 2 hours
  5. customsulfur was removed by filtration
  6. washThe ethyl acetate layer was washed with a saturated saline solution
  7. dry with materialdried over anhydrous magnesium sulfate
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-0b5aa2b412a340c1bda4f6fd0695096c
Source dataset
uspto-grants-2015_12
Patent number
US09200008B2

Reaction notes

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