反应详情

The 1-ethoxycarbonyl-3,4-dihydro-2-methylisoquinolinium monomethylsulfate solution obtained by Reference Example A4 was added with 60 ml of water and 22.4 g (322 mmol) of hydroxylamine hydrochloride in a flask. The mixture was stirred at room temperature for six hours. The reaction mixture was added with 120 ml of ethyl acetate, and then the pH was adjusted at 9 to 10 with about 103 g of aqueous sodium hydroxide solution (25%) to yield precipitation. The solution was stirred at 5° C. for 30 minutes. Then, the precipitation was filtered, washed with ethyl acetate, and dried to obtain 42.2 g (169 mmol, yield 55%, 3 steps) of ethyl hydroxyimino-[2-(2-methylaminoethyl)phenyl]acetate as white crystals.

1. customto yield
2. customprecipitation
3. stirringThe solution was stirred at 5° C. for 30 minutes
4. customThen, the precipitation
5. filtrationwas filtered
6. washwashed with ethyl acetate
7. customdried