Acetic Acid → 8-chloro-1,4-dihydrothiochromeno[4,3-c]pyrazole

HRID 2308937Notes

Reaction equation

HRID 2308937 reaction equation
[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[S:10][CH2:9][C:8](=[CH:11][N:12](C)C)[C:7](=O)[C:6]=2[CH:16]=1.O.[NH2:18]N.C(O)(=O)C>CO>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[S:10][CH2:9][C:8]3[CH:11]=[N:12][NH:18][C:7]=3[C:6]=2[CH:16]=1

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 24654Hydrazine hydrate (1:1)HCID 38135366-chloro-2,3-dihydro-3-dimethylaminomethylene-4H-1-benzothiopyran-4-one

Product 1

HCID 27396788-chloro-1,4-dihydrothiochromeno[4,3-c]pyrazole

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of 6-chloro-2,3-dihydro-3-dimethylaminomethylene-4H-1-benzothiopyran-4-one (7 g), hydrazine hydrate (2.01 ml), and acetic acid (2.37 ml) in methanol (140 ml) was stirred at room temperature for 5 hours and then evaporated in vacuo. To the residue was added aqueous sodium bicarbonate and extracted with ethyl acetate. The extract was washed with water, dried over magnesium sulfate, and evaporated in vacuo. The residue solid was recrystallized from ethyl acetate to give 8-chloro-1,4-dihydro[1]benzothiopyrano[4,3-c]pyrazole (2.85 g).

Workup

  1. customevaporated in vacuo
  2. additionTo the residue was added aqueous sodium bicarbonate
  3. extractionextracted with ethyl acetate
  4. washThe extract was washed with water
  5. dry with materialdried over magnesium sulfate
  6. customevaporated in vacuo
  7. customThe residue solid was recrystallized from ethyl acetate

Sources & evidence

ORD record
ord-64ee2668a0f64786bf28656156860fa4
Source dataset
uspto-grants-1987_09
Patent number
US04692444

Reaction notes

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