Lawesson's reagent → 2-[5-(4-chloro-phenyl)-1-(2,4-dichloro-phenyl)-4-methyl-1H-pyrazol-3-yl]-1,5,5-trimethyl-1,5-dihydro-imidazole-4-thione

HRID 1805200Notes

Reaction equation

HRID 1805200 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[N:12]([C:13]3[CH:18]=[CH:17][C:16]([Cl:19])=[CH:15][C:14]=3[Cl:20])[N:11]=[C:10]([C:21]3[N:22]([CH3:29])[C:23]([CH3:28])([CH3:27])[C:24](=O)[N:25]=3)[C:9]=2[CH3:30])=[CH:4][CH:3]=1.COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=[S:40])=CC=1>C1(C)C=CC=CC=1>[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[N:12]([C:13]3[CH:18]=[CH:17][C:16]([Cl:19])=[CH:15][C:14]=3[Cl:20])[N:11]=[C:10]([C:21]3[N:22]([CH3:29])[C:23]([CH3:28])([CH3:27])[C:24](=[S:40])[N:25]=3)[C:9]=2[CH3:30])=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 87949Lawesson's reagentHCID 441917474H-Imidazol-4-one, 2-[5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazol-3-yl]-1,5-dihydro-1,5,5-trimethyl-

Product 1

HCID 441918112-[5-(4-chloro-phenyl)-1-(2,4-dichloro-phenyl)-4-methyl-1H-pyrazol-3-yl]-1,5,5-trimethyl-1,5-dihydro-imidazole-4-thioneYield 77%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
60 °C

Procedure

To a solution of compound 6 (98 mg, 0.22 mmol) in toluene (5 mL) was added Lawesson's reagent (150 mg, 0.37 mmol) in one portion. The resulting mixture was heated at 60° C. for 4 h, then poured into ice water. The resulting mixture was extracted with ethyl acetate (2×30 mL). The combined extracts were washed with water, saturated aqueous sodium bicarbonate, and brine, dried over anhydrous sodium sulfate, filtered, and concentrated. The residue was purified by flash chromatography on silica gel with hexanes/ethyl acetate (7:3) to give the desired thioketone 21 (78 mg, 77%) as a yellow solid. 1H NMR (400 MHz, CDCl3) δ 7.48 (d, 1H), 7.32 (d, 2H), 7.28 (dd, 1H), 7.22 (d, 1H), 7.08 (d, 2H), 3.62 (s, 3H), 2.48 (s, 3H), 1.55 (s, 6H); ESMS m/z: 477.0 (M+1).

Workup

  1. extractionThe resulting mixture was extracted with ethyl acetate (2×30 mL)
  2. washThe combined extracts were washed with water, saturated aqueous sodium bicarbonate, and brine
  3. dry with materialdried over anhydrous sodium sulfate
  4. filtrationfiltered
  5. concentrationconcentrated
  6. customThe residue was purified by flash chromatography on silica gel with hexanes/ethyl acetate (7:3)

Sources & evidence

ORD record
ord-2740fb5741b144eca356a075d576303b
Source dataset
uspto-grants-2013_01
Patent number
US08354442B2

Reaction notes

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