Acetic Acid → ethyl 2-chloro-6H-thieno[2,3-b]pyrrole-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of ethyl 6H-thieno[2,3-b]pyrrole-5-carboxylate (0.21 g, 1.1 mmol) in CHCl3 (2.0 mL) cooled in an ice bath to 0° C., was added AcOH (glacial, 2.0 mL) followed by portionwise addition of N-chlorosuccinimide (NCS) (0.14 g, 1.1 mmol) over 2 h. After the addition of NCS was complete, the ice bath was removed and the reaction was allowed to stir at 23° C. for 5 h. After 5 h the CHCl3 was removed in vacuo and the remaining mixture was combined with aqueous 4N NaOH (10 mL) and extracted with EtOAc (3×30 mL). The combined organics were dried over Na2SO4, filtered and the solvent removed in vacuo. Purification by flash column chromatography (25% EtOAc in hexanes) afforded ethyl 2-chloro-6H-thieno[2,3-b]pyrrole-5-carboxylate (0.16 g, 66% yield).

Provenance & Evidence