Lawesson's reagent → N-(3,5-difluorophenyl)-2-pyridinecarbothioamide

HRID 477030Notes

Reaction equation

HRID 477030 reaction equation
[F:1][C:2]1[CH:3]=[C:4]([NH:9][C:10]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][N:13]=2)=O)[CH:5]=[C:6]([F:8])[CH:7]=1.COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=[S:27])=CC=1>C1(C)C=CC=CC=1>[F:1][C:2]1[CH:3]=[C:4]([NH:9][C:10]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][N:13]=2)=[S:27])[CH:5]=[C:6]([F:8])[CH:7]=1

Participants

4

Reactant 2

HCID 87949Lawesson's reagentHCID 14510254HCID 14510254, compound

Product 1

HCID 3081188N-(3,5-difluorophenyl)-2-pyridinecarbothioamideYield 92.3%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

N-(3,5-Difluorophenyl)-2-pyridinecarboxamide (7.00 g, 29.9 mmol) was treated with Lawesson's reagent (6.28 g, 15.5 mmol) in toluene (90 mL) at reflux temperature for 4 hours. The solvent was removed, and the residue was dissolved in dichloromethane, preadsorbed onto silica gel, and flash chromatographed (300 g of silica gel eluted with 10% ethyl acetate in petroleum ether). Recrystallization from a mixture of ethyl acetate and hexane afforded N-(3,5-difluorophenyl)-2-pyridinecarbothioamide (3.58 g, 48%) as a yellow solid, m.p. 140°-142° C. Overall yield 33%.

Workup

  1. temperatureat reflux temperature for 4 hours
  2. customThe solvent was removed
  3. dissolutionthe residue was dissolved in dichloromethane
  4. customchromatographed
  5. wash(300 g of silica gel eluted with 10% ethyl acetate in petroleum ether)
  6. customRecrystallization
  7. additionfrom a mixture of ethyl acetate and hexane

Sources & evidence

ORD record
ord-2bd72e1fe08e464f90f78d4de7ed4387
Source dataset
uspto-grants-1989_12
Patent number
US04886821

Reaction notes

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