5-Chlorothiophene-2-Sulfonamide → 5-Chloro-thiophene-2-sulfonic acid amino-(4,4-dimethyl-4,5-dihydro-pyrazol-1-yl)-methyleneamide

HRID 1484460Notes

Reaction equation

HRID 1484460 reaction equation
CS[C:3]([N:5]1[CH2:9][C:8]([CH3:11])([CH3:10])[CH:7]=[N:6]1)=[NH:4].[Cl:12][C:13]1[S:17][C:16]([S:18]([NH2:21])(=[O:20])=[O:19])=[CH:15][CH:14]=1>C(#N)C>[NH2:4][C:3]([N:5]1[CH2:9][C:8]([CH3:11])([CH3:10])[CH:7]=[N:6]1)=[N:21][S:18]([C:16]1[S:17][C:13]([Cl:12])=[CH:14][CH:15]=1)(=[O:20])=[O:19]

Participants

4

Reactant 2

HCID 12413015-Chlorothiophene-2-SulfonamideHCID 673594724,4-Dimethyl-4,5-dihydro-pyrazole-1-carboximidothioic acid methyl ester

Product 1

HCID 699280035-Chloro-thiophene-2-sulfonic acid amino-(4,4-dimethyl-4,5-dihydro-pyrazol-1-yl)-methyleneamideYield 80%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

1.0 g (1 mol equiv.) 4,4-Dimethyl-4,5-dihydro-pyrazole-1-carboximidothioic acid methyl ester and 1.21 g (1.05 mol equiv.) 5-chloro-thiophene-2-sulfonic acid amide were added to 10 mL acetonitrile. The reaction mixture was refluxed overnight, and volatiles were removed under reduced pressure. The residue was taken up in ethyl acetate and extracted with 2N NaOH. The organic layer was dried over Na2SO4, filtered and evaporated to dryness. Purification by flash chromatography on silica gel (Et2O:PA=2:1) afforded 1.58 g (80%) 5-chloro-thiophene-2-sulfonic acid amino-(4,4-dimethyl-4,5-dihydro-pyrazol-1-yl)-methyleneamide. 1H NMR (400 MHz, CDCl3) δ 1.25 (s, 6H), 3.63 (s, 2H), 6.00-6.50 (br.s., 1H), 6.79 (s, 1H), 6.85 (d, J=4.0 Hz, 1H), 7.10-7.35 (br.s., 1H), 7.37 (d, J=4.0 Hz, 1H).

Workup

  1. temperatureThe reaction mixture was refluxed overnight
  2. customvolatiles were removed under reduced pressure
  3. extractionextracted with 2N NaOH
  4. dry with materialThe organic layer was dried over Na2SO4
  5. filtrationfiltered
  6. customevaporated to dryness
  7. customPurification by flash chromatography on silica gel (Et2O:PA=2:1)

Sources & evidence

ORD record
ord-d64b9ca59a8e4e949e654aa1e85e3f50
Source dataset
uspto-grants-2016_08
Patent number
US09422244B2

Reaction notes

Loading…