Thionyl Chloride → 3-(Methylsulfonyl)-5-(trifluoromethyl)benzonitrile

Participants

Reaction Conditions

Reaction Steps

In a 3-neck 500 mL round-bottomed flask, 3-(methylsulfonyl)-5-(trifluoromethyl)benzamide (7 g, 1 eq.) was dissolved in DMF (70 mL, 10 Vol) and added thionylchloride (3.8 mL, 2.0 eq.) and reaction mixture was refluxed to 90° C. for 12 h. The progress of the reaction was followed by TLC analysis on silica gel with 30% ethyl acetate -Hexane as mobile phase and visualization with UV, SM Rf=0.20 and Product Rf=0.35. Reaction mixture was brought to room temperature and quenched into the ice-water slurry (300 mL) and neutralized with sodium bicarbonate solution. Compound was extracted in the ethyl acetate (100 mL×3). Organic layer was washed with brine solution (100 mL) followed by drying using anhydrous sodium sulphate. Organic layer was concentrated under reduced pressure to afford 5.0 g of crude compound, yield (95.0%). The crude reaction mixture was purified by column chromatography using silica 60/120 using ethyl acetate:hexane as mobile phase. The column (5×20 cm) was packed in hexane and started eluting in ethyl acetate in gradient manner starting with fraction collection (25-mL fractions) from 15% to 20% ethyl acetate in hexane. Compound started eluting with 15% ethylacetate in hexane. Fraction containing such TLC profile was collected together to obtain pure compound (4 g), Yield (62%); Mass: (ES−) 247.97 (M−1).

Provenance & Evidence