Sulfuric Acid → Clopidogrel

Participants

Reaction Conditions

Reaction Steps

5 g of (+)-(2-chlorophenyl)-(6,7-dihydro-4H-thieno[3,2-c]pyrid-5-yl)acetamide was dissolved in 35 ml methanol and the solution was chilled to 0 to −5° C. 15 mL (0.28 mole) of conc. H2SO4 (98%) was added slowly in 1 hr maintaining the temperature till −5° C. After the completion of addition the reaction mixture was stirred at room temperature for 30 min. The solution was refluxed at 60° C. for 36 hrs. The reaction mixture was cooled to room temperature and the solvent was distilled off under reduced pressure. The residue was added to 200 mL chilled water was added and cooled to −5° C. The pH of reaction mixture was adjusted between 9 to 10 using aq. sodium carbonate. The residue was extracted with 100 mL ethyl acetate. The organic layer was dried over anhydrous Na2SO4, and evaporated under vacuum. The combined eluent was evaporated at reduced pressure to yield 3.2 g of purified product purified by column chromatography, using hexane: ethyl acetate (9:1) as eluent.

Provenance & Evidence