Acetonitrile → Leflunomide

HRID 743053Notes

Reaction equation

HRID 743053 reaction equation
C[C:2]1([C:7](Cl)=[O:8])[CH2:6][O:5][N:4]=[CH:3]1.[F:10][C:11]([F:20])([F:19])[C:12]1[CH:18]=[CH:17][C:15]([NH2:16])=[CH:14][CH:13]=1.[C:21](#N)C>>[F:10][C:11]([F:19])([F:20])[C:12]1[CH:18]=[CH:17][C:15]([NH:16][C:7]([C:2]2[CH:3]=[N:4][O:5][C:6]=2[CH3:21])=[O:8])=[CH:14][CH:13]=1

Participants

4

Reactant 3

HCID 6342Acetonitrile2×HCID 99644-(Trifluoromethyl)anilineHCID 194241224-Methylisoxazole-4-carbonyl chloride

Product 1

HCID 3899Leflunomide

Procedure

A solution of 0.05 mol of 4-methylisoxazole-4-carbonyl chloride (7.3 g) in 20 ml of acetonitrile is added dropwise, at room temperature, to a solution of 0.1 mol of 4-trifluoromethylaniline (16.1 g) in 150 ml of acetonitrile. After stirring for 20 minutes, the precipitated 4-trifluoromethylaniline hydrochloride is filtered off with suction and washed twice with 20 ml of acetonitrile on each occasion, and the combined filtrates are concentrated under reduced pressure. Yield: 12.8 g of white, crystalline N-(4-trifluoromethylphenyl)-5-methylisoxa-zole-4-catboxamide (leflunomide).

Workup

  1. filtrationthe precipitated 4-trifluoromethylaniline hydrochloride is filtered off with suction
  2. washwashed twice with 20 ml of acetonitrile on each occasion
  3. concentrationthe combined filtrates are concentrated under reduced pressure

Sources & evidence

ORD record
ord-6745093b6020437e97f708f7be76b7ba
Source dataset
uspto-grants-1996_09
Patent number
US05556870

Reaction notes

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