Hydrochloric Acid → 6-Chloro-3-methyl-5-nitro-1,2-benzisothiazole

HRID 428397Notes

Reaction equation

HRID 428397 reaction equation
N(OC(C)(C)C)=O.N[C:9]1[C:18]([N+:19]([O-:21])=[O:20])=[CH:17][C:12]2[C:13]([CH3:16])=[N:14][S:15][C:11]=2[CH:10]=1.[ClH:22]>C(#N)C.[Cu](Cl)Cl>[Cl:22][C:9]1[C:18]([N+:19]([O-:21])=[O:20])=[CH:17][C:12]2[C:13]([CH3:16])=[N:14][S:15][C:11]=2[CH:10]=1

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 10906Tert-Butyl nitriteHCID 183144986-Amino-3-methyl-5-nitro-1,2-benzisothiazole

Product 1

HCID 183144816-Chloro-3-methyl-5-nitro-1,2-benzisothiazole

Reagents, catalysts & solvents 2

HCID 24014Cupric ChlorideCatalystHCID 6342AcetonitrileSolvent

Conditions

Temperature
65 °C

Procedure

A mixture of tert-butyl nitrite (3.30 mL, 0.0278 mol) and copper(II) chloride (2.98 g, 0.0222 mol) in acetonitrile is heated to 65° C., treated portionwise with 6-amino-3-methyl-5-nitro-1,2-benzisothiazole (3.88 g, 0.0185 mol), stirred at 65° C., cooled to room temperature, and poured into 20% hydrochloric acid. The resultant aqueous mixture is extracted with ethyl acetate. The organic extracts are combined, washed with 20% hydrochloric acid, dried over anhydrous magnesium sulfate, and concentrated in vacuo to obtain a solid. Flash column chromatography of the solid using silica gel and methylene chloride/hexanes solutions (1:1 and 3:1) gives the title product as a pale, yellow solid (2.54 g, mp 156-158° C.) which is identified by NMR spectral analyses.

Workup

  1. temperaturecooled to room temperature
  2. extractionThe resultant aqueous mixture is extracted with ethyl acetate
  3. washwashed with 20% hydrochloric acid
  4. dry with materialdried over anhydrous magnesium sulfate
  5. concentrationconcentrated in vacuo
  6. customto obtain a solid

Sources & evidence

ORD record
ord-31178e7d6a9c4c6e8871c081174f899a
Source dataset
uspto-grants-2001_11
Patent number
US06313295B1

Reaction notes

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