Hydrochloric Acid → HCID 135720097, compound

HRID 36070Notes

Reaction equation

HRID 36070 reaction equation
[N+:1]([C:4]1[CH:5]=[CH:6][C:7]2[O:12][C:11]([CH3:14])([CH3:13])[C:10](=[O:15])[CH2:9][C:8]=2[CH:16]=1)([O-:3])=[O:2].[CH3:17][N:18]=[C:19]=[S:20].CC(C)([O-])C.[K+].Cl>CN(C)C=O>[CH3:17][NH:18][C:19]([C:9]1[C:8]2[CH:16]=[C:4]([N+:1]([O-:3])=[O:2])[CH:5]=[CH:6][C:7]=2[O:12][C:11]([CH3:13])([CH3:14])[C:10]=1[OH:15])=[S:20]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 11167Methyl isothiocyanateHCID 15234740HCID 15234740, compoundHCID 23665647Potassium tert-butoxide

Product 1

HCID 135720097HCID 135720097, compoundYield 54.7%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a mixture of 3.2 g of 6-nitro-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-3-one, 1.2 g of methyl isothiocyanate, and 40 ml of dried N,N-dimethylformamide was added 1.9 g of potassium t-butoxide while stirring under cooling with ice. The mixture was stirred for 3 hours under ice-cooling and then allowed to stand for 12 hours. Ice-water was added thereto, and the mixture was made acidic with hydrochloric acid and then extracted with methylene chloride. The organic layer was re-extracted with 2N NaOH. The aqueous layer was made acidic with hydrochloric acid and re-extracted with methylene chloride. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The residue was subjected to silica gel column chromatography (developing solution: n-hexane:ethyl acetate =10:1) and recrystallized from a mixed solvent of methylene chloride and n-hexane to obtain 2.33 g of N-methyl-6-nitro-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-4-carbothioamide.

Workup

  1. temperatureunder cooling with ice
  2. stirringThe mixture was stirred for 3 hours under ice-
  3. temperaturecooling
  4. extractionextracted with methylene chloride
  5. extractionThe organic layer was re-extracted with 2N NaOH
  6. extractionre-extracted with methylene chloride
  7. dry with materialThe organic layer was dried over magnesium sulfate
  8. concentrationconcentrated under reduced pressure
  9. customrecrystallized from a mixed solvent of methylene chloride and n-hexane

Sources & evidence

ORD record
ord-dab387b734504e3c896db81db7ad4625
Source dataset
uspto-grants-1995_05
Patent number
US05412117

Reaction notes

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