2H-Naphth(1,8-cd)isothiazole 1,1-dioxide → 8-Amino-1-naphthalenethiol

HRID 235681Notes

Reaction equation

HRID 235681 reaction equation
[H-].[Al+3].[Li+].[H-].[H-].[H-].[CH:7]1[CH:12]=[C:11]2[NH:13][S:14]([C:17]3=[CH:18][CH:19]=[CH:20][C:9](=[C:10]23)[CH:8]=1)(=O)=O>CCOCC.O1CCCC1>[NH2:13][C:11]1[CH:12]=[CH:7][CH:8]=[C:9]2[C:10]=1[C:17]([SH:14])=[CH:18][CH:19]=[CH:20]2

Participants

5

Reactant 2

HCID 690522H-Naphth(1,8-cd)isothiazole 1,1-dioxideHCID 21226445Aluminium lithium hydride

Product 1

HCID 125743828-Amino-1-naphthalenethiolYield 79%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a mixture of 3.0 g of lithium aluminum hydride in 150 mL of anhydrous ether was added dropwise a solution of 4.0 g of 1,8-naphthosultam in 15 mL of anhydrous tetrahydrofuran over a period of 45 minutes while maintaining a gentle reflux. After completion of the addition, the yellow mixture was refluxed for another hour. The mixture was cooled in an ice-bath and the excess of lithium aluminum hydride was destroyed by dropwise addition of 10 mL of water. The resulting mixture was acidified with 200 mL of 4N sulfuric acid and extracted with ether (3×100 mL). The ether extracts were washed with water (75 mL) and dried (magnesium sulfate). Removal of the solvent gave 2.7 g (79%) of 8-amino-1-naphthalenethiol, mp. 68°-70°. This compound is sensitive to air, and therefore was used immediately.

Workup

  1. temperaturewhile maintaining a gentle reflux
  2. additionAfter completion of the addition
  3. temperaturethe yellow mixture was refluxed for another hour
  4. temperatureThe mixture was cooled in an ice-bath
  5. customthe excess of lithium aluminum hydride was destroyed by dropwise addition of 10 mL of water
  6. extractionextracted with ether (3×100 mL)
  7. washThe ether extracts were washed with water (75 mL)
  8. dry with materialdried (magnesium sulfate)
  9. customRemoval of the solvent

Sources & evidence

ORD record
ord-6657d6d8e79d436fa47bf71e3576ef7d
Source dataset
uspto-grants-1987_02
Patent number
US04640930

Reaction notes

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