Hydrochloric Acid → 2-Chloro-6-trifluoromethylbenzothiazole

HRID 30880

Reaction equation

HRID 30880 reaction equation
N(OC(C)(C)C)=O.N[C:9]1[S:10][C:11]2[CH:17]=[C:16]([C:18]([F:21])([F:20])[F:19])[CH:15]=[CH:14][C:12]=2[N:13]=1.[ClH:22]>C(#N)C.[Cu]>[Cl:22][C:9]1[S:10][C:11]2[CH:17]=[C:16]([C:18]([F:21])([F:20])[F:19])[CH:15]=[CH:14][C:12]=2[N:13]=1

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 10906Tert-Butyl nitriteHCID 27359552-Amino-6-(trifluoromethyl)benzothiazole

Product 1

HCID 114704192-Chloro-6-trifluoromethylbenzothiazoleYield 92%

Reagents, catalysts & solvents 2

HCID 23978CopperCatalystHCID 6342AcetonitrileSolvent2×

Procedure

In a three-necked flask fitted with a condenser, a suspension of copper II chloride (370 mg, 2.75 mmol) in acetonitrile (5 mL) was treated with tert-butyl nitrite (0.41 mL, 3.44 mmol) and stirred at rt for 10 minutes. A solution of 2-amino-6-trifluoromethylbenzthiazole (500 mg, 2.29 mmol) in acetonitrile (1 mL) was then added dropwise. The mixture was heated at 65° C. for 30 minutes, then cooled and diluted with an excess of 1 N aqueous hydrochloric acid solution. The mixture was extracted with ethyl acetate. The organic phase was separated, dried (MgSO4), and concentrated under reduced pressure. An orange semi-solid (501 mg, 92%) was obtained and used without further purification. 1H NMR (300 MHz, CDCl3) δ 8.10-8.05 (m, 2H), 7.74 (d, 1H); LC-MS m/z 238.2 (MH+), ret. time 3.76 min TLC Rf=0.50 (9:1 hexanes/ethyl acetate).

Workup

  1. customIn a three-necked flask fitted with a condenser
  2. temperatureThe mixture was heated at 65° C. for 30 minutes
  3. temperaturecooled
  4. extractionThe mixture was extracted with ethyl acetate
  5. customThe organic phase was separated
  6. dry with materialdried (MgSO4)
  7. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-3c70de483c3c4057b3925f136c8252ae
Source dataset
uspto-grants-2008_09
Patent number
US07423156B2

Linked notes

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