Hydrochloric Acid → 8-Chloro-1-methyl-1,4-dihydro[1]benzothiopyrano[4,3-c]pyrazole

HRID 2308940Notes

Reaction equation

HRID 2308940 reaction equation
Cl.C(O[C:7]([N:9](C)[NH:10][CH:11]=[C:12]1[C:17](=O)[C:16]2[CH:19]=[C:20]([Cl:23])[CH:21]=[CH:22][C:15]=2[S:14][CH2:13]1)=O)(C)(C)C>CO>[Cl:23][C:20]1[CH:21]=[CH:22][C:15]2[S:14][CH2:13][C:12]3[CH:11]=[N:10][N:9]([CH3:7])[C:17]=3[C:16]=2[CH:19]=1

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 53870822HCID 53870822, compound

Product 1

HCID 201864418-Chloro-1-methyl-1,4-dihydro[1]benzothiopyrano[4,3-c]pyrazoleYield 73.7%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Procedure

A solution of hydrogen chloride in methanol (225 ml) was added to a suspension of 3-(2-t-butoxycarbonyl-2-methylhydrazinomethylene)-6-chloro-2,3-dihydro-4H-1-benzothiopyran-4-one (54.14 g) in methanol (550 ml). After being stirred at ambient temperature for 8 hours, the mixture was evaporated in vacuo and the residue was extracted with ethyl acetate after an addition of water. The extract was washed with aqueous sodium bicarbonate and then water, dried over magnesium sulfate, and evaporated in vacuo to give 8-chloro-1-methyl-1,4-dihydro[1]benzothiopyrano[4,3-c]pyrazole (26.63 g).

Workup

  1. customthe mixture was evaporated in vacuo
  2. extractionthe residue was extracted with ethyl acetate
  3. additionafter an addition of water
  4. washThe extract was washed with aqueous sodium bicarbonate
  5. dry with materialwater, dried over magnesium sulfate
  6. customevaporated in vacuo

Sources & evidence

ORD record
ord-fa65e1bdc7fa4b1ea536b81d587d3b25
Source dataset
uspto-grants-1987_09
Patent number
US04692444

Reaction notes

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