Tetrahydrofuran → 3,4-dihydro-3-hydroxy-N-methyl-6-nitrospiro[2H-1-benzopyran-2,4'-tetrahydropyran]-4-carbothioamide

HRID 264843Notes

Reaction equation

HRID 264843 reaction equation
[OH:1][C:2]1[C:7]2([CH2:12][CH2:11][O:10][CH2:9][CH2:8]2)[O:6][C:5]2[CH:13]=[CH:14][C:15]([N+:17]([O-:19])=[O:18])=[CH:16][C:4]=2[C:3]=1[C:20](=[S:23])[NH:21][CH3:22].O1CCCC1.[BH4-].[Na+]>CO>[OH:1][CH:2]1[C:7]2([CH2:12][CH2:11][O:10][CH2:9][CH2:8]2)[O:6][C:5]2[CH:13]=[CH:14][C:15]([N+:17]([O-:19])=[O:18])=[CH:16][C:4]=2[CH:3]1[C:20](=[S:23])[NH:21][CH3:22]

Participants

5

Reactant 3

HCID 8028TetrahydrofuranHCID 4311764Sodium borohydrideHCID 136381157HCID 136381157, compound

Product 1

HCID 190370263,4-dihydro-3-hydroxy-N-methyl-6-nitrospiro[2H-1-benzopyran-2,4'-tetrahydropyran]-4-carbothioamideYield 45.7%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a mixture of 3.7 g of 3-hydroxy-N-methyl-6-nitrospiro[2H-1-benzopyran-2,4'-tetrahydropyran]-4-carbothioamide, 100 ml of tetrahydrofuran and 100 ml of methanol was added 2.8 g of sodium borohydride (NaBH4) with stirring under ice-cooling, and the mixture was stirred under ice-cooling for 30 minutes and then at room temperature for 24 hours. The reaction solution was vacuum-distilled, water was added therein and the resultant mixture was extracted with methylene chloride. An organic layer was washed with water and dried. The solvent was distilled to obtain 1.7 g of 3,4-dihydro-3-hydroxy-N-methyl-6-nitrospiro[2H-1-benzopyran-2,4'-tetrahydropyran]-4-carbothioamide. Subsequently, to 1.5 g of it were added 2.1 g of p-toluenesulfonyl chloride and 60 ml of pyridine. After the mixture was refluxed with heating for 1 hour, the solvent was distilled. Ice water was added to the residue and the reaction solution was acidified to be hydrochloric acid and extracted with methylene chloride. An organic layer was washed with water and dried, and the solvent was distilled. The residue was purified according to silica gel column chromatography (developing solution, MeOH:CH2Cl2 =1:99) to obtain 1.2 g of N-methyl-6-nitrospiro[2H-1-benzopyran-2,4'-tetrahydropyran]-4-carboxamide with a melting point of 183°-184° C.

Workup

  1. temperaturecooling
  2. stirringthe mixture was stirred under ice-
  3. temperaturecooling for 30 minutes
  4. distillationThe reaction solution was vacuum-distilled
  5. additionwater was added
  6. extractionthe resultant mixture was extracted with methylene chloride
  7. washAn organic layer was washed with water
  8. customdried
  9. distillationThe solvent was distilled

Sources & evidence

ORD record
ord-80cf1db6605d41d2a58d25f974bd5213
Source dataset
uspto-grants-1997_07
Patent number
US05646308

Reaction notes

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