Tributylamine → 1,2-Benzisothiazole, 3-chloro-5-nitro-

HRID 369602Notes

Reaction equation

HRID 369602 reaction equation
[N+:1]([C:4]1[CH:5]=[CH:6][C:7]2[S:11][NH:10][C:9](=O)[C:8]=2[CH:13]=1)([O-:3])=[O:2].P(Cl)(Cl)([Cl:16])=O.C(N(CCCC)CCCC)CCC>C(Cl)Cl>[Cl:16][C:9]1[C:8]2[CH:13]=[C:4]([N+:1]([O-:3])=[O:2])[CH:5]=[CH:6][C:7]=2[S:11][N:10]=1

Participants

5

Reactant 3

HCID 7622TributylamineHCID 24813Phosphorus oxychlorideHCID 131869501,2-Benzisothiazol-3(2H)-one, 5-nitro-

Product 1

HCID 1980981,2-Benzisothiazole, 3-chloro-5-nitro-

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
109 °C

Procedure

A mixture of 5-nitro-1,2-benzisothiazol-3(2H)-one (10.0 g, 0.0510 mol), phosphorus oxychloride (40.0 mL, 0.429 mol) and tributylamine (12.0 mL, 0.050 mol) is heated at 103-115° C. for six hours, stirred at room temperature overnight, and poured into an ice-water mixture. The resultant aqueous mixture is extracted with methylene chloride. The combined organic extracts are washed sequentially with water and saturated sodium hydrogen carbonate solution, dried over anhydrous sodium sulfate, and concentrated in vacuo to obtain a gum. Column chromatography of the gum using silica gel and methylene chloride gives the title product as an orange-yellow solid which is identified by NMR spectral analysis.

Workup

  1. extractionThe resultant aqueous mixture is extracted with methylene chloride
  2. washThe combined organic extracts are washed sequentially with water and saturated sodium hydrogen carbonate solution
  3. dry with materialdried over anhydrous sodium sulfate
  4. concentrationconcentrated in vacuo
  5. customto obtain a gum

Sources & evidence

ORD record
ord-df813a069e7a41c8952c0b549f387a26
Source dataset
uspto-grants-2000_10
Patent number
US06140270

Reaction notes

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