Hydrochloric Acid → Ethyl 1,3-benzothiazole-2-carboxylate

HRID 22661Notes

Reaction equation

HRID 22661 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[SH:8].[C:9](OCC)(=O)[C:10]([O:12][CH2:13][CH3:14])=[O:11].O.Cl>CCO>[S:8]1[C:3]2[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=2[N:1]=[C:9]1[C:10]([O:12][CH2:13][CH3:14])=[O:11]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 962WaterHCID 7268Diethyl OxalateHCID 87132-Aminothiophenol

Product 1

HCID 640708Ethyl 1,3-benzothiazole-2-carboxylateYield 36.2%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of 2-aminothiophenol (10.7 mL, 0.1 mol) in diethyl oxalate (27.3 mL, 0.2 mol) is heated at reflux for 4 hr. The solution is cooled to rt and poured into a solution consisting of water (150 mL), conc. HCl (50 mL) and 95% EtOH (70 mL). With stirring, the oil dissolved and a solid formed. The solution is cooled in an ice bath, the solid is collected by vacuum filtration and the solids are washed with a solution consisting of EtOH/water (25/75) to afford a dark solid. This material is purified by crystallization from hot (68° C.) ligroin to yield ethyl 2-benzothiazolecarboxylate (7.5 g, 36%): Elemental analysis for C10H9NO2S: Calc: C, 57.95; H, 4.38; N, 6.76. Found: C, 57.99; H, 4.28; N, 6.78.

Workup

  1. temperatureat reflux for 4 hr
  2. additionpoured into a solution
  3. dissolutionthe oil dissolved
  4. customa solid formed
  5. temperatureThe solution is cooled in an ice bath
  6. filtrationthe solid is collected by vacuum filtration
  7. washthe solids are washed with a solution
  8. customto afford a dark solid
  9. customThis material is purified by crystallization from hot (68° C.) ligroin

Sources & evidence

ORD record
ord-08f8001d29c14f0b8f97fb256f161cd1
Source dataset
uspto-grants-2005_02
Patent number
US06849620B2

Reaction notes

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