Dimethylformamide → N-methyl-6-cyano-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-4-carbothioamide

HRID 36062

Reaction equation

HRID 36062 reaction equation
[C:1]([C:3]1[CH:4]=[CH:5][C:6]2[O:11][C:10]([CH3:13])([CH3:12])[C:9](=[O:14])[CH2:8][C:7]=2[CH:15]=1)#[N:2].[CH3:16][N:17]=[C:18]=[S:19].CN(C)C=O.CC(C)([O-])C.[K+]>C(O)(=O)C>[CH3:16][NH:17][C:18]([C:8]1[C:7]2[CH:15]=[C:3]([C:1]#[N:2])[CH:4]=[CH:5][C:6]=2[O:11][C:10]([CH3:13])([CH3:12])[C:9]=1[OH:14])=[S:19]

Participants

6

Reactant 4

HCID 6228DimethylformamideHCID 11167Methyl isothiocyanateHCID 148695546-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-3-oneHCID 23665647Potassium tert-butoxide

Product 1

HCID 135720096N-methyl-6-cyano-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-4-carbothioamideYield 68.5%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

To a mixture of 1.5 g of 6-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-3-one, 0.6 g of methyl isothio-cyanate, and 15 ml of dried N,N-dimethylformamide was added 0.93 g of potassium t-butoxide with stirring under ice-cooling, followed by stirring for 4 hours under ice-cooling. Ice-water was added to the reaction mixture, and the mixture was made acidic with acetic acid and then extracted with diethyl ether. The ether layer was washed with water and dried over sodium sulfate. The ether layer was removed by distillation, and the residue was recrystallized from ethanol to yield 1.4 g of N-methyl-6-cyano-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-4-carbothioamide represented by formula shown below.

Workup

  1. temperaturecooling
  2. stirringby stirring for 4 hours under ice-
  3. temperaturecooling
  4. extractionextracted with diethyl ether
  5. washThe ether layer was washed with water
  6. dry with materialdried over sodium sulfate
  7. customThe ether layer was removed by distillation
  8. customthe residue was recrystallized from ethanol

Sources & evidence

ORD record
ord-de48dd21366944da9ff0804dea9a9368
Source dataset
uspto-grants-1995_05
Patent number
US05412117

Linked notes

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