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

HRID 1198454Notes

Reaction equation

HRID 1198454 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 α-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 α-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-b5e6a78265c04af5a4cef421a34315aa
Source dataset
uspto-grants-1994_01
Patent number
US05281592

Reaction notes

Loading…