5-Amino-3-methylisoxazole → N-(3-methyl-5-isoxazolyl)-5-bromothiophene-2-sulfonamide
Reaction equation
[Br:1][C:2]1[S:6][C:5]([S:7](Cl)(=[O:9])=[O:8])=[CH:4][CH:3]=1.[NH2:11][C:12]1[O:16][N:15]=[C:14]([CH3:17])[CH:13]=1>>[CH3:17][C:14]1[CH:13]=[C:12]([NH:11][S:7]([C:5]2[S:6][C:2]([Br:1])=[CH:3][CH:4]=2)(=[O:9])=[O:8])[O:16][N:15]=1Participants
3
Procedure
N-(3-methyl-5-isoxazolyl)-5-bromothiophene-2-sulfonamide was prepared in the same manner as described in Example 14 from 5-bromothiophene-2-sulfonyl chloride and 5-amino-3-methyl isoxazole. Purification was achieved by extraction of the crude sulfonamide into aqueous 2N NaOH, washing of the aqueous layer with ethyl acetate and acidification, using concentrated HCl, to pH ~2. Re-extraction into ethyl acetate was followed by washing of the organic material with water, brine and drying over magnesium sulfate. After evaporation of solvents, a brownish solid remained which was sufficiently pure to use in the next step.
Workup
- customPurification
- extraction