Chloroacetic Acid → 2-(Chloromethyl)benzothiazole

HRID 747287Notes

Reaction equation

HRID 747287 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[SH:8].[Cl:9][CH2:10][C:11](O)=[O:12].C(=O)([O-])[O-].[K+].[K+]>O>[Cl:9][CH2:10][C:11]1[O:12][C:3]2[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=2[N:1]=1.[Cl:9][CH2:10][C:11]1[S:8][C:3]2[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=2[N:1]=1

Participants

6

Reactant 3

HCID 300Chloroacetic AcidHCID 87132-AminothiophenolHCID 11430Potassium Carbonate

Product 2

HCID 3049782-(Chloromethyl)benzothiazoleHCID 20619892-(Chloromethyl)-1,3-benzoxazole

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
120 °C

Procedure

Using literature procedures (Addison, A. W.; Nageswara Rao, T.; Wahlgren, C. G. J. Heterocyclic Chem. 1983, 20, 1481-1484) a substituted 2-aminophenol (or a 2-aminothiophenol (5 mmol)) was mixed with chloroacetic acid (940 mg, 10 mmol) in polyphosphoric acid (5 mL), and the viscous mixture was then heated to 120° C. for 3 hours. The reaction was then cooled, and diluted with water (˜20 mL) and then neutralized with potassium carbonate to pH˜7. The mixture was then extracted with ethyl acetate, and the combined organic fractions were then dried over MgSO4 and concentrated. The residue was then purified by column chromatography on silica gel (50% ethyl acetate in hexanes) to afford the desired 2-chloromethylbenzoxazole (or 2-chloromethylbenzothiazole).

Workup

  1. temperatureThe reaction was then cooled
  2. extractionThe mixture was then extracted with ethyl acetate
  3. dry with materialthe combined organic fractions were then dried over MgSO4
  4. concentrationconcentrated
  5. customThe residue was then purified by column chromatography on silica gel (50% ethyl acetate in hexanes)

Sources & evidence

ORD record
ord-8f7acb362f0e49d58ed2200d769d9224
Source dataset
uspto-grants-2008_07
Patent number
US07396840B2

Reaction notes

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