Leflunomide → 5-Methyl-4-(4-trifluoromethylphenyl)aminothiocarbonylisoxazole

HRID 962800Notes

Reaction equation

HRID 962800 reaction equation
[CH3:1][C:2]1[O:6][N:5]=[CH:4][C:3]=1[C:7]([NH:9][C:10]1[CH:15]=[CH:14][C:13]([C:16]([F:19])([F:18])[F:17])=[CH:12][CH:11]=1)=O.COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=[S:29])=CC=1>C1(C)C=CC=CC=1>[CH3:1][C:2]1[O:6][N:5]=[CH:4][C:3]=1[C:7]([NH:9][C:10]1[CH:15]=[CH:14][C:13]([C:16]([F:19])([F:18])[F:17])=[CH:12][CH:11]=1)=[S:29]

Participants

4

Reactant 2

HCID 3899LeflunomideHCID 87949Lawesson's reagent

Product 1

HCID 158588075-Methyl-4-(4-trifluoromethylphenyl)aminothiocarbonylisoxazoleYield 64.9%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A solution of 24 grams of 5-methyl-4-(4-trifluoromethylphenyl)aminocarbonylisoxazole and 39 grams of Lawesson's reagent [2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide] in 400 ml of toluene was refluxed for three hours. Upon cooling of mixture to room temperature, all the solid was filtered off and the filtrate was concentrated. The resulting crude product from the filtrate was then purified on a silica gel column with 3% methanol in dichloromethane to yield 16.5 grams of 5-methyl-4-(4-trifluoromethylphenyl)aminothiocarbonylisoxazole.

Workup

  1. filtrationall the solid was filtered off
  2. concentrationthe filtrate was concentrated
  3. customThe resulting crude product from the filtrate was then purified on a silica gel column with 3% methanol in dichloromethane

Sources & evidence

ORD record
ord-0ba013fbf8d44496afefa6d2bba4daac
Source dataset
uspto-grants-1998_06
Patent number
US05760066

Reaction notes

Loading…