Benzaldehyde → 1-Phenyl-4-(5-methyl-2-thienyl)-1,4-butanedione

HRID 2165126Notes

Reaction equation

HRID 2165126 reaction equation
[C-]#N.[Na+].[CH:4](=[O:11])[C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1.Cl.CN(C)[CH2:15][CH2:16][C:17]([C:19]1[S:20][C:21]([CH3:24])=[CH:22][CH:23]=1)=[O:18].[OH-].[NH4+]>CN(C)C=O.O>[C:5]1([C:4](=[O:11])[CH2:15][CH2:16][C:17]([C:19]2[S:20][C:21]([CH3:24])=[CH:22][CH:23]=2)=[O:18])[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1

Participants

7

Reactant 4

HCID 240BenzaldehydeHCID 8929Sodium CyanideHCID 14923Ammonium HydroxideHCID 126434363-Dimethylamino-1-(5-methyl-2-thienyl)-propan-1-one hydrochloride

Product 1

HCID 135558071-Phenyl-4-(5-methyl-2-thienyl)-1,4-butanedione

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent2×

Procedure

To a stirred suspension of 1.2 grams (0.025 mole) of sodium cyanide in 70 ml of dimethylformamide was added dropwise a solution of 5.2 grams (10 moles) of freshly distilled benzaldehyde in 40 ml of dimethylformamide. The complete addition required 20 minutes. The reaction mixture was stirred for one hour. Separately, while the mixture stirred, 10.0 grams (0.043 mole) of 3-dimethylamino-1-(5-methyl-2-thienyl)-propan-1-one hydrochloride was made alkaline in water with ammonium hydroxide, extracted with ethyl acetate, dried with sodium sulfate, filtered and concentrated. The so-prepared free Mannich base was dissolved in 40 ml of dimethylformamide and added dropwise to the benzaldehyde/sodium cyanide reaction mixture. The complete addition required one hour. The reaction mixture was stirred for an additional 16 hours, then concentrated under reduced pressure to a residual solid. The solid was taken up in water and extracted with three 100 ml portions of chloroform. The combined extracts were washed with water and dried with sodium sulfate. The organic layer was concentrated under reduced pressure to a solid residue. The solid was recrystallized from ethanol-water to give 8.3 grams of 1-phenyl-4-(5-methyl-2-thienyl)-1,4-butanedione; m.p. 122.5° C.

Workup

  1. additionThe complete addition required 20 minutes
  2. stirringSeparately, while the mixture stirred
  3. extractionextracted with ethyl acetate
  4. dry with materialdried with sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated
  7. dissolutionThe so-prepared free Mannich base was dissolved in 40 ml of dimethylformamide
  8. additionadded dropwise to the benzaldehyde/sodium cyanide reaction mixture
  9. additionThe complete addition required one hour
  10. stirringThe reaction mixture was stirred for an additional 16 hours
  11. concentrationconcentrated under reduced pressure to a residual solid
  12. extractionextracted with three 100 ml portions of chloroform
  13. washThe combined extracts were washed with water
  14. dry with materialdried with sodium sulfate
  15. concentrationThe organic layer was concentrated under reduced pressure to a solid residue
  16. customThe solid was recrystallized from ethanol-water

Sources & evidence

ORD record
ord-99d4b77e78e14b8fa510fa2629c814a7
Source dataset
uspto-grants-1990_07
Patent number
US04939165

Reaction notes

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