Ethanol → 7-chloro-2-(4-chlorophenyl)-3-oxo-3,4-dihydro-2H-1,4-benzothiazine

HRID 5843Notes

Reaction equation

HRID 5843 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][C:5]([Cl:8])=[CH:4][C:3]=1[SH:9].[OH-].[K+].[CH2:12]([OH:14])[CH3:13]>>[Cl:8][C:5]1[CH:6]=[CH:7][C:2]2[NH:1][C:12](=[O:14])[CH:13]([C:2]3[CH:7]=[CH:6][C:5]([Cl:8])=[CH:4][CH:3]=3)[S:9][C:3]=2[CH:4]=1

Participants

4

Reactant 3

HCID 702EthanolHCID 14797Potassium HydroxideHCID 27375182-Amino-5-chlorobenzenethiol

Product 1

HCID 189844307-chloro-2-(4-chlorophenyl)-3-oxo-3,4-dihydro-2H-1,4-benzothiazine

Procedure

To a solution of 2-amino-5-chlorothiophenol (4.49 g) in ethanol (30 ml) is added 96 % potassium hydroxide (1.63 g), and the mixture is distilled to remove ethanol. The resulting solid material is suspended in toluene (70 ml) and thereto is added methyl ° -bromo-4-chlorophenylacetate (7.38 g), and the mixture is refluxed overnight. The reaction mixture is concentrated, and the resulting precipitate is separated by filtration, washed, dried, and then recrystallized from tetrahydrofuran-n-hexane to give 7-chloro-2-(4-chlorophenyl)-3-oxo-3,4-dihydro-2H-1,4-benzothiazine (6.58 g) as crystals. M.p. 230°-233.5° C.

Workup

  1. distillationthe mixture is distilled
  2. customto remove ethanol
  3. additionis added methyl ° -bromo-4-chlorophenylacetate (7.38 g)
  4. temperaturethe mixture is refluxed overnight
  5. concentrationThe reaction mixture is concentrated
  6. customthe resulting precipitate is separated by filtration
  7. washwashed
  8. customdried
  9. customrecrystallized from tetrahydrofuran-n-hexane

Sources & evidence

ORD record
ord-82405db35af04c76bc822593939f548f
Source dataset
uspto-grants-1993_09
Patent number
US05246929

Reaction notes

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