Dimethylformamide → 4,5-Dihydro-8-methylthio-2-phenylbenzo[2,1-c:3,4-b']dithiophene-6-carboxylic acid

HRID 1108356Notes

Reaction equation

HRID 1108356 reaction equation
Cl[C:2]1[C:10]2[C:6](=[C:7]([C:13]([O:15]CC)=[O:14])[S:8][C:9]=2[S:11][CH3:12])[CH2:5][CH2:4][C:3]=1[CH:18]=O.C(=O)([O-])[O-].[K+].[K+].CN(C)C=O.[OH-].[Na+]>C(O)C.O.Cl>[CH3:12][S:11][C:9]1[S:8][C:7]([C:13]([OH:15])=[O:14])=[C:6]2[CH2:5][CH2:4][C:3]3[CH:18]=[C:7]([C:6]4[CH:10]=[CH:2][CH:3]=[CH:4][CH:5]=4)[S:8][C:2]=3[C:10]=12

Participants

8

Reactant 4

HCID 6228DimethylformamideHCID 11430Potassium CarbonateHCID 14798Sodium HydroxideHCID 2778781Ethyl 4-chloro-5-formyl-6,7-dihydro-3-methylthiobenzo[c]thiophene-1-carboxylate

Product 1

HCID 183883114,5-Dihydro-8-methylthio-2-phenylbenzo[2,1-c:3,4-b']dithiophene-6-carboxylic acid

Reagents, catalysts & solvents 3

HCID 313Hydrochloric AcidCatalystHCID 702EthanolSolventHCID 962WaterSolvent3×

Procedure

Ethyl 4-chloro-5-formyl-6,7-dihydro-3-methylthiobenzo[c]thiophene-1-carboxylate (1.32 g), methyl α-mercaptophenyl acetate (0.76 g) and potassium carbonate (0.69 g) were added to N,N-dimethylformamide (15 ml). The mixture was stirred at room temperature for 2 hours. The reaction mixture was poured over water, and extracted with ethyl acetate. The organic layer was washed with water and dried (MgSO4), after which the solvent was distilled off. The residue was subjected to silica gel column chromatography and eluted with ethyl acetate-hexane (1:5, v/v) to yield yellow powder. The powder was dissolved in ethanol (10 ml), to which an aqueous sodium hydroxide (0.10 g) in water (2 ml) was added. The obtained solution was stirred at 60° C. for 7 hours. To the reaction solution was added concentrated hydrochloric acid (1 drop). After the mixture was poured over water, it was extracted with ethyl acetate. The organic layer was washed with water and dried (MgSO4), after which the solvent was distilled off. The residue was subjected to silica gel column chromatography and eluted with chloroform-methanol to yield 4,5-dihydro-8-methylthio-2-phenylbenzo[2,1-c:3,4-b']dithiophene-6-carboxylic acid, which was then recrystallized from ethyl acetate-hexane. Yellow prisms. Melting point 215-217° C.

Workup

  1. extractionextracted with ethyl acetate
  2. washThe organic layer was washed with water
  3. dry with materialdried (MgSO4)
  4. distillationafter which the solvent was distilled off
  5. washeluted with ethyl acetate-hexane (1:5
  6. customv/v) to yield yellow powder
  7. additionwas added
  8. stirringThe obtained solution was stirred at 60° C. for 7 hours
  9. extractionwas extracted with ethyl acetate
  10. washThe organic layer was washed with water
  11. dry with materialdried (MgSO4)
  12. distillationafter which the solvent was distilled off
  13. washeluted with chloroform-methanol

Sources & evidence

ORD record
ord-f9372a96f25e44d3b240eafd0896588b
Source dataset
uspto-grants-2000_05
Patent number
US06066658

Reaction notes

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