Sodium Hydroxide → 1-Chloroisoquinoline-5-carboxylic acid--hydrogen chloride (1/1)

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Reaction Steps

A solution of 5-carbethoxy-1-chloroisoquinoline (German Patent DE 2816863) (1.75 g, 7.4 mmol) and NaOH (0.8 g, 20 mmol) in MeOH-H20 (50 mL, 4:1) was stirred at 23° C. for 5 h. The solvents were evaporated in vacuo and the residue partioned between CH2Cl2 and aqueous NaOH (2 M). The aqueous phase was acidified with conc HCl and extracted with copious EtOAc (×4). The combined organics were washed with brine, dried over MgSO4 and concentrated in vacuo to leave 5-carboxy-1-chloroisoquinoline hydrochloride (1.8 g, 7.4 mmol) as a white solid.

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