(4-Chlorophenyl)hydrazine → 2-(4-chlorophenyl)-4,4a, 5,6-tetrahydrothieno[2',3':2,3]thiopyrano[4,5-c]pyridazin-3(2H)-one

HRID 1681825Notes

Reaction equation

HRID 1681825 reaction equation
O=[C:2]1[CH:7]([CH2:8][C:9]([OH:11])=O)[CH2:6][S:5][C:4]2[S:12][CH:13]=[CH:14][C:3]1=2.[Cl:15][C:16]1[CH:21]=[CH:20][C:19]([NH:22][NH2:23])=[CH:18][CH:17]=1>C(O)C>[Cl:15][C:16]1[CH:21]=[CH:20][C:19]([N:22]2[C:9](=[O:11])[CH2:8][CH:7]3[CH2:6][S:5][C:4]4[S:12][CH:13]=[CH:14][C:3]=4[C:2]3=[N:23]2)=[CH:18][CH:17]=1

Participants

4

Reactant 2

HCID 70624(4-Chlorophenyl)hydrazineHCID 152250354-oxo-5,6-dihydro-4H-thieno[2,3-b]thiopyran-5-acetic acid

Product 1

HCID 190167892-(4-chlorophenyl)-4,4a, 5,6-tetrahydrothieno[2',3':2,3]thiopyrano[4,5-c]pyridazin-3(2H)-oneYield 73.3%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 4.0 g of 4-oxo-5,6-dihydro-4H-thieno-[2,3-b]thiopyran-5-acetic acid and 3.3 g of 4-chlorophenylhydrazine in 70 ml of ethanol is refluxed under heating for 6.5 hours. After cooling, the reaction mixture is concentrated under reduced pressure. The residue is dissolved in 50 ml of acetic acid and the solution is refluxed under heating for 2 hours. Then, the resultant mixture is concentrated under reduced pressure, the residue is subjected to chromatography on silica gel and eluted with chloroform. The crystals obtained from the fraction are recrystallized from a mixed solvent of chloroform and ethanol to give 4.3 g of 2-(4-chlorophenyl)-4a,5-dihydro-2H-thieno[2',3':2,3]thiopyrano[4,5-c]pyridazin-3(4H)-one as pale brown crystals, melting at 162°-164° C.

Workup

  1. temperatureis refluxed
  2. temperatureunder heating for 6.5 hours
  3. temperatureAfter cooling
  4. concentrationthe reaction mixture is concentrated under reduced pressure
  5. dissolutionThe residue is dissolved in 50 ml of acetic acid
  6. temperaturethe solution is refluxed
  7. temperatureunder heating for 2 hours
  8. concentrationThen, the resultant mixture is concentrated under reduced pressure
  9. washeluted with chloroform
  10. customThe crystals obtained from the fraction
  11. customare recrystallized from a mixed solvent of chloroform and ethanol

Sources & evidence

ORD record
ord-036a15097a1344aab4edce9b3beb70b4
Source dataset
uspto-grants-1992_12
Patent number
US05175162

Reaction notes

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