Hydrochloric Acid → Clopidogrel

Participants

Reaction Steps

(±) Methyl α-(7-hydroxy-4,5,6,7-tetrahydro-5-thieno[3,2-c]pyridyl)-o-chlorophenylacetate (23) (0.21 g, 0.622 mmol) was dissolved in acetic acid (4 mL) and treated sequentially with conc. HCl and SnCl2 dihydrate (0.28 g, 1.243 mmol). The reaction was allowed to stir overnight and the solvent was evaporated under vacuum. The residue was partitioned between ethyl acetate and saturated sodium bicarbonate and the ethyl acetate layer was concentrated to provide clopidogrel free base as an oily product (0.16 g). 1H-NMR (CDCl3, ppm) 7.7 (1H, dd), 7.35 (1H, m), 7.2-7.35 (2H, m), 7.2 (1H, d), 6.68 (1H, dd), 4.95 (1H, s), 4.68 (1H, bs), 3.5-4.0 (2H, m), 3.75 (3H, s), 2.9 (4 H, s).

Provenance & Evidence