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

HRID 5844

Reaction equation

HRID 5844 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-9f13dedfca454f268811c8281667b82c
Source dataset
uspto-grants-1993_09
Patent number
US05246929

Linked notes

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