p-Toluenesulfonic acid → N-(6-chloro-pyrazin-2-yl)-4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide

HRID 484691Notes

Reaction equation

HRID 484691 reaction equation
[OH:1][C:2]1[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:6]=2[S:5](=[O:13])(=[O:12])[N:4]([CH3:14])[C:3]=1[C:15]([NH:17][C:18]1[CH:23]=CC=CC=1)=[O:16].NC1C=[N:29][CH:28]=[C:27]([Cl:31])[N:26]=1.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C(C)=CC=CC=1>[Cl:31][C:27]1[N:26]=[C:18]([NH:17][C:15]([C:3]2[N:4]([CH3:14])[S:5](=[O:12])(=[O:13])[C:6]3[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=3[C:2]=2[OH:1])=[O:16])[CH:23]=[N:29][CH:28]=1

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 1184582-Amino-6-ChloropyrazineHCID 54684780W7477

Product 1

HCID 54703135N-(6-chloro-pyrazin-2-yl)-4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxideYield 23%

Reagents, catalysts & solvents 1

HCID 7237O-XyleneSolvent

Procedure

1.0 g (3 mmols) of 4-hydroxy-2-methyl-N-phenyl-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide were refluxed with 1.3 g (10 mmols) of 2-amino-6-chloro-pyrazine and 0.1 g of p-toluenesulfonic acid in 250 ml of xylene for 72 hours. After cooling, the reaction mixture was washed with 2N hydrochloric acid and then with water, then dried and concentrated by evaporation in vacuo. The residue was purified column chromatography (Merck silicagel 60; particle size: 0.2-0.5 mm; eluant: chloroform/ethanol 90:10) and yielded 0.25 g (23% of theory) of N-(6-chloro-pyrazin-2-yl)-4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide.

Workup

  1. temperatureAfter cooling
  2. washthe reaction mixture was washed with 2N hydrochloric acid
  3. dry with materialwith water, then dried
  4. concentrationconcentrated by evaporation in vacuo
  5. customThe residue was purified column chromatography (Merck silicagel 60; particle size: 0.2-0.5 mm; eluant: chloroform/ethanol 90:10)

Sources & evidence

ORD record
ord-5af9c3448c424fe09485da41cedb0b72
Source dataset
uspto-grants-1985_08
Patent number
US04533664

Reaction notes

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