Hydrochloric Acid → 2-Chloro-6-trifluoromethylbenzothiazole

HRID 30891

Reaction equation

HRID 30891 reaction equation
Cl[C:2]1[CH:8]=[C:7]([C:9]([F:12])([F:11])[F:10])[CH:6]=[CH:5][C:3]=1[NH2:4].[C:13](=[S:18])(OCC)[S-].[K+].[ClH:20]>CN(C=O)C>[Cl:20][C:13]1[S:18][C:2]2[CH:8]=[C:7]([C:9]([F:12])([F:11])[F:10])[CH:6]=[CH:5][C:3]=2[N:4]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 1620012-Chloro-4-trifluoromethylanilineHCID 2735045Potassium ethylxanthate

Product 1

HCID 114704192-Chloro-6-trifluoromethylbenzothiazoleYield 99%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
130 °C

Procedure

A mixture of 2-chloro-4-trifluoromethylaniline (15.0 g, 76.7 mmol) and potassium O-ethyl dithiocarbonate (29.5 g, 184.1 mmol) in 75 mL anhydrous DMF was heated at 130° C. overnight under a nitrogen atmosphere. The reaction mixture was cooled to rt, and then 1 N HCl solution (200 mL) was added with stirring to induce precipitation. After the mixture was stirred for 30 minutes, the solid precipitate was collected by filtration and rinsed with water. The filter cake was dissolved in 100 mL EtOAc, and the solution was dried over Na2SO4. EtOAc was removed by rotary evaporation, and the residue was dried in vacuo to afford the desired product as a white solid (18.0 g, 99%). 1H NMR (DMSO-d6) δ 14.00 (bs, 1H), 8.20 (s, 1H), 7.70 (d, 1H), 7.40 (d, 1H); GC-EIMS m/z 235 (M+).

Workup

  1. temperatureThe reaction mixture was cooled to rt
  2. customprecipitation
  3. stirringAfter the mixture was stirred for 30 minutes
  4. filtrationthe solid precipitate was collected by filtration
  5. washrinsed with water
  6. dissolutionThe filter cake was dissolved in 100 mL EtOAc
  7. dry with materialthe solution was dried over Na2SO4
  8. customEtOAc was removed by rotary evaporation
  9. customthe residue was dried in vacuo

Sources & evidence

ORD record
ord-271aedb946a045a0bdfcbdee70c87dee
Source dataset
uspto-grants-2008_09
Patent number
US07423156B2

Linked notes

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