反应详情

While stirring at a temperature of from 0° to 5°, a solution of 1.42 g (16.4 mmol) of acrylic acid methyl ester in 10 ml of methanol is added dropwise within a period of 15 minutes to a solution of 3.0 g (16.5 mmol) of 3-aminomethyl-6-fluoro-chroman in 80 ml of methanol. The reaction mixture is then stirred for 16 hours at from 0° to 5° and then concentrated by evaporation in vacuo. The oily residue is chromatographed on 250 g of silica gel (0.040-0.063 mm) with ethyl acetate as eluant, yielding 2.85 g of N-[(6-fluorochroman-3-yl)methyl]-N-(2-methoxycarbonylethyl)-amine in the form of a light-yellow oil. The N-[(6-fluorochroman-3-yl)methyl]-N-(2-methoxycarbonylethyl)-amine hydrochloride, prepared therefrom with hydrochloric acid in diethyl ether, crystallizes from acetone/diethyl ether and melts at 163°-165°. The N-[(6-fluorochroman-3-yl)methyl]-N-(2-methoxycarbonylethyl)-amine cyclamate, prepared from the crude base with N-cyclohexyl-sulfamic acid, crystallizes from acetone and melts at 155°-156°.

1. stirringThe reaction mixture is then stirred for 16 hours at from 0° to 5°
2. concentrationconcentrated by evaporation in vacuo
3. customThe oily residue is chromatographed on 250 g of silica gel (0.040-0.063 mm) with ethyl acetate as eluant