Tetrahydrofuran → HCID 19037045, compound

HRID 264829Notes

Reaction equation

HRID 264829 reaction equation
[OH:1][C:2]1[C:3]([CH2:20][O:21][CH3:22])([CH3:19])[O:4][C:5]2[CH:15]=[CH:14][C:13]([N+:16]([O-:18])=[O:17])=[CH:12][C:6]=2[C:7]=1[C:8](=[S:11])[NH:9][CH3:10].O1CCCC1.[BH4-].[Na+]>CO>[CH3:10][NH:9][C:8]([CH:7]1[C:6]2[CH:12]=[C:13]([N+:16]([O-:18])=[O:17])[CH:14]=[CH:15][C:5]=2[O:4][C:3]([CH2:20][O:21][CH3:22])([CH3:19])[CH:2]1[OH:1])=[S:11]

Participants

5

Reactant 3

HCID 8028TetrahydrofuranHCID 4311764Sodium borohydrideHCID 136381155HCID 136381155, compound

Product 1

HCID 19037045HCID 19037045, compoundYield 39%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a mixture of 5.1 g of 3-hydroxy-2-methoxymethyl-N,2-dimethyl-6-nitro-2H-1-benzopyran-4-carbothioamide, 75 ml of tetrahydrofuran and 125 ml of methanol was added 3.0 g of sodium borohydride (NaBH4). The mixture was stirred under ice-cooling for 2 hours and subsequently stirred at room temperature for 24 hours. The reaction solution was vacuum-distilled and water was added to it and the resultant solution was extracted with methylene chloride. After an organic layer was washed with water and dried, the solvent was distilled to obtain 2 g of N-methyl-3,4-dihydro-3-hydroxy-2-methoxymethyl-2-methyl-6-nitro-2H-1-benzopyran-4-carbothioamide. Subsequently, to 1 g of the obtained benzopyran derivative were added 1.17 g of p-toluenesulfonyl chloride and 25 ml of pyridine. The resultant mixture was refluxed with heating for 1 hour and the solvent was distilled. Ice water was added to the residue and it 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 resultant residue was purified according to silica gel column chromatography (developing solution, hexane:AcOEt=1:1) to obtain 680 mg of 2-methoxymethyl-N,2-dimethyl-6-nitro-2H-1-benzopyran-4-carboxamide with a melting point of 128°-130° C.

Workup

  1. temperaturecooling for 2 hours
  2. stirringsubsequently stirred at room temperature for 24 hours
  3. distillationThe reaction solution was vacuum-distilled
  4. additionwater was added to it
  5. extractionthe resultant solution was extracted with methylene chloride
  6. washAfter an organic layer was washed with water
  7. customdried
  8. distillationthe solvent was distilled

Sources & evidence

ORD record
ord-2af6201918134b44a27265afdba1ae45
Source dataset
uspto-grants-1997_07
Patent number
US05646308

Reaction notes

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