反应详情

Oxalyl chloride (0.908 g, 0.60 ml, 7.16 mmol) was added dropwise at 0° C. to a solution of 5-(4-Chlorophenyl)-2,4-dimethyl-1-(4-sulfamoylphenyl)-1H-pyrrole-3-carboxylic acid (step 2, 1.45 g, 3.58 mmol) in dichloromethane (50 ml)/DMF (0.544 g, 0.50 ml, 7.16 m mol). Mixture was allowed to come at room temperature and stirred for 1 hr. under nitrogen atmosphere. The completion of reaction was monitored by TLC. The mixture was concentrated under reduced pressure under nitrogen atmosphere. To this residue was added N,O-dimethylhydroxylamine hydrochloride (0.690 g, 7.16 mmol) in dry dichloromethane (50 ml) at 0° C. followed by the addition of triethylamine (1.44 g, 2.0 ml, 14.32 mmol,) under stirring. The reaction mixture was stirred at room temperature for 2 hr. The completion of reaction was monitored by TLC. The solvent was removed under reduced pressure. The residue so obtained was taken in dichloromethane (50 ml), washed with water (2×25 ml.) and organic layers separated were dried over anhydrous sodium sulphate, filtered and concentrated at reduced pressure to get a crude product. This crude product was purified by column chromatography over silica gel (100-200 mesh) using 0.8% methanol in dichloromethane as an eluent to yield the title compound (0.763 g, 42%).

1. customto come at room temperature
2. customThe completion of reaction
3. concentrationThe mixture was concentrated under reduced pressure under nitrogen atmosphere
4. stirringunder stirring
5. stirringThe reaction mixture was stirred at room temperature for 2 hr
6. customThe completion of reaction
7. customThe solvent was removed under reduced pressure
8. customThe residue so obtained
9. washwashed with water (2×25 ml.) and organic layers
10. customseparated
11. dry with materialwere dried over anhydrous sodium sulphate
12. filtrationfiltered
13. concentrationconcentrated at reduced pressure
14. customto get a crude product
15. customThis crude product was purified by column chromatography over silica gel (100-200 mesh)