Carbon Disulfide → 6-Chloro-1,4-dihydro-2H-3,1-benzothiazine-2-thione

HRID 1414711Notes

Reaction equation

HRID 1414711 reaction equation
[C:1](=[S:3])=[S:2].[OH-].[K+].[NH2:6][C:7]1[CH:14]=[CH:13][C:12]([Cl:15])=[CH:11][C:8]=1[CH2:9]O>C(O)C>[Cl:15][C:12]1[CH:13]=[CH:14][C:7]2[NH:6][C:1](=[S:3])[S:2][CH2:9][C:8]=2[CH:11]=1

Participants

5

Reactant 3

HCID 6348Carbon DisulfideHCID 14797Potassium HydroxideHCID 5867542-Amino-5-chlorobenzyl alcohol

Product 1

HCID 214848846-Chloro-1,4-dihydro-2H-3,1-benzothiazine-2-thioneYield 102.4%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Carbon disulfide (180 ml, 3.0 moles) was added dropwise to a stirred solution of 84 g (1.5 moles) of potassium hydroxide in 400 ml of absolute ethanol with external cooling. To this mixture was added 157 g (1.0 mole) of 2-amino-5-chlorobenzyl alcohol. The reaction mixture was heated under reflux for 20 hours and the solvent was removed by distillation. The solid residue was stirred with 2000 ml of 10% aqueous potassium hydroxide, and the mixture was filtered to remove neutral impurities. The clear filtrate was made acidic with dil. hydrochloric acid, and the solid which was deposited was collected by filtration to give 221 g (100%) of product. Recrystallization from methanol gave an analytical sample, m.p. 217°-222°.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureunder reflux for 20 hours
  3. customthe solvent was removed by distillation
  4. filtrationthe mixture was filtered
  5. customto remove neutral impurities
  6. filtrationthe solid which was deposited was collected by filtration

Sources & evidence

ORD record
ord-12936774e37a4df0ad30a1979ad2d399
Source dataset
uspto-grants-1977_01
Patent number
US04002620

Reaction notes

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