Pyridine → N-(3,4-Dimethyl-5-isoxazolyl)-2-methylbenzo[b]thiophene-3-sulfonamide

HRID 234329Notes

Reaction equation

HRID 234329 reaction equation
[CH3:1][C:2]1[S:6][C:5]2[CH:7]=[CH:8][CH:9]=[CH:10][C:4]=2[C:3]=1[S:11](Cl)(=[O:13])=[O:12].[CH3:15][C:16]1[C:20]([CH3:21])=[C:19]([NH2:22])[O:18][N:17]=1.N1C=CC=CC=1>CN(C)C1C=CN=CC=1.C(OCC)(=O)C>[CH3:15][C:16]1[C:20]([CH3:21])=[C:19]([NH:22][S:11]([C:3]2[C:4]3[CH:10]=[CH:9][CH:8]=[CH:7][C:5]=3[S:6][C:2]=2[CH3:1])(=[O:13])=[O:12])[O:18][N:17]=1

Participants

6

Reactant 3

HCID 1049PyridineHCID 883175-Amino-3,4-dimethylisoxazoleHCID 229984492-Methyl-1-benzothiophene-3-sulfonyl chloride

Product 1

HCID 17798006N-(3,4-Dimethyl-5-isoxazolyl)-2-methylbenzo[b]thiophene-3-sulfonamide

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 8857Ethyl AcetateSolvent

Procedure

2-Methylbenzo[b]thiophene-3-sulfonyl chloride (1.7 mmoles, 0.41 g) was added to a solution of 3,4-dimethyl-5-aminoisoxazole (0.75 mmoles, 84 mg), 4-dimethylaminopyridine (DMAP; 50 mg) and pyridine (5 ml) at ambient temperature. After 24 h, the reaction mixture was diluted with ethyl acetate (50 ml) and washed with 2% HCl (3×50 ml). The organic phase was dried (MgSO4), filtered and concentrated to collect a brown-orange solid, which was dissolved in a solution of methanol (10 ml) and NaOH (60 mg). The solution was stirred 1 h at ambient temperature, then the methanol was evaporated and the resulting residue was diluted with 2% HCl (50 ml), and extracted with ethyl acetate (75 ml). The organic phase was dried (MgSO4), filtered and concentrated to collect a tan solid. Recrystallization from chloroform and hexanes resulted in 93 mg (38%) of N-(3,4-dimethyl-5-isoxazolyl)-2-methylbenzo[b]thiophene-3-sulfonamide as light yellow crystals, m.p. 174°-176° C.

Workup

  1. washwashed with 2% HCl (3×50 ml)
  2. dry with materialThe organic phase was dried (MgSO4)
  3. filtrationfiltered
  4. concentrationconcentrated
  5. customto collect a brown-orange solid, which
  6. dissolutionwas dissolved in a solution of methanol (10 ml) and NaOH (60 mg)
  7. customthe methanol was evaporated
  8. additionthe resulting residue was diluted with 2% HCl (50 ml)
  9. extractionextracted with ethyl acetate (75 ml)
  10. dry with materialThe organic phase was dried (MgSO4)
  11. filtrationfiltered
  12. concentrationconcentrated
  13. customto collect a tan solid
  14. customRecrystallization from chloroform and hexanes
  15. customresulted in 93 mg (38%) of N-(3,4-dimethyl-5-isoxazolyl)-2-methylbenzo[b]thiophene-3-sulfonamide as light yellow crystals

Sources & evidence

ORD record
ord-f3e491ee45734500a1f6640fa7369574
Source dataset
uspto-grants-1997_01
Patent number
US05594021

Reaction notes

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