Hydrochloric Acid → N-Hydroxyphthalimide

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Reaction Steps

To a flask was added 50 mL of 1N sodium hydroxide aqueous solution, and powdery N-cyclohexyloxyphthalimide (4.9 g, 20 mmol) was slowly added thereto with stirring. The mixture was stirred at 97° C. for 5 hours to obtain an aqueous solution containing sodium salt of phthalic acid. To the aqueous solution was added diluted hydrochloric acid to convert into phthalic acid, and phthalic acid was recovered by condensation and filtration. To a flask were added the phthalic acid, 50 mL of pyridine and 0.05 g of sulfuric acid and stirred at 95° C. for 4 hours to obtain a mixture containing phthalic anhydride. Hydroxylamine hydrochloride NH2OH.HCl (2.8 g, 40 mmol) was added to the mixture, stirred at 50° C. for 3 hours to form N-hydroxyphthalimide (2.6 g, yield 81%).

Provenance & Evidence