Hydrochloric Acid → 4-Amino-3-bromo-2,6-dimethylthieno[2,3-b]pyridine-5-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of ethyl 4-amino-3-bromo-2,6-dimethylthieno[2,3-b]pyridine-5-carboxylate (5 g, 15.19 mmol) (Description 6) in ethanol (50 mL) was added aqueous NaOH (3M) (20.25 mL, 60.8 mmol) and the mixture stirred at 100° C. for 1 h. The reaction mixture was cooled and combined with material (4.43 g) from a similar reaction. The combined solution was acidified with aqueous HCl (1M) to pH 6-7. Ethanol was removed in vacuo. Water (50 mL) was added and the mixture extracted with DCM (5×50 mL). The combined organics were dried over MgSO4, filtered and solvent removed in vacuo, to afford the title compound (2.98 g). LCMS (A) m/z: 301/303 [M+1]+, Rt 0.73 min (acidic).

Provenance & Evidence