Thiophene → 3-oxo-2-(2-thienyl)-3,4-dihydro-2H-1,4-benzothiazine

HRID 1439867Notes

Reaction equation

HRID 1439867 reaction equation
Cl[CH:2]1[C:7](=[O:8])[NH:6][C:5]2[CH:9]=[CH:10][CH:11]=[CH:12][C:4]=2[S:3]1.[S:13]1[CH:17]=[CH:16][CH:15]=[CH:14]1>C(Cl)Cl>[O:8]=[C:7]1[NH:6][C:5]2[CH:9]=[CH:10][CH:11]=[CH:12][C:4]=2[S:3][CH:2]1[C:14]1[S:13][CH:17]=[CH:16][CH:15]=1

Participants

4

Reactant 2

HCID 8030ThiopheneHCID 122185992H-1,4-Benzothiazin-3(4H)-one, 2-chloro-

Product 1

HCID 189844063-oxo-2-(2-thienyl)-3,4-dihydro-2H-1,4-benzothiazineYield 70.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 2-chloro-3-oxo-3,4-dihydro-2H-1,4-benzothiazine (9.38 g) and thiophene (7.91 g) in methylene chloride (250 ml) is added in portions stannic chloride (12.2 g) at 0° to 5° C. After stirring at the same temperature for 45 minutes, the mixture is poured into ice water, and the organic layer is separated. The aqueous layer is extracted with ethyl acetate, and the ethyl acetate layer is combined with the above organic layer and distilled to remove the solvent. The resulting solid material is recrystallized from ethanol to give 3-oxo-2-(2-thienyl)-3,4-dihydro-2H-1,4-benzothiazine (8.17 g) as crystals.

Workup

  1. customthe organic layer is separated
  2. extractionThe aqueous layer is extracted with ethyl acetate
  3. distillationdistilled
  4. customto remove the solvent
  5. customThe resulting solid material is recrystallized from ethanol

Sources & evidence

ORD record
ord-447649090ebb4efdb257883de18da4a2
Source dataset
uspto-grants-1996_03
Patent number
US05496815

Reaction notes

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