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

HRID 1198455Notes

Reaction equation

HRID 1198455 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 soltuion 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-c3680547a8d94970836b4c35c52d96ac
Source dataset
uspto-grants-1994_01
Patent number
US05281592

Reaction notes

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