Water → 1-(2-(4-((2,3-dihydro(1,4)dioxino(2,3-c)pyridin-7-ylmethyl)amino)piperidin-1-yl)ethyl)-7-fluoro-1,5-naphthyridin-2(1H)-one

Participants

Reaction Steps

A solution of 3.03 g of tert-butyl (2,3-dihydro(1,4)dioxino(2,3-c)pyridin-7-ylmethyl)(1-(2-(7-fluoro-2-oxo-1,5-naphthyridin-1(2H)-yl)ethyl)piperidin-4-yl)carbamate in 45 mL of trifluoroacetic acid was stirred for 1 hour and 30 minutes at room temperature. The reaction mixture was cooled with ice, added with 30 mL of water and 30 mL of ethyl acetate, and adjusted to pH 10 with a 2 mol/L sodium hydroxide aqueous solution. The organic layer was separated and the aqueous layer was extracted 7 times with ethyl acetate. The organic layer was combined therewith and the solvent was concentrated to 10 mL under reduced pressure, whereby insoluble matter was filtered out. The solvent was evaporated under reduced pressure, and the obtained residue was purified by basic silica gel column chromatography [eluate; chloroform:methanol=92:8], recrystallized from 3 mL of ethyl acetate to give 0.611 g of 1-(2-(4-((2,3-dihydro(1,4)dioxino(2,3-c)pyridin-7-ylmethyl)amino)piperidin-1-yl)ethyl)-7-fluoro-1,5-naphthyridin-2(1H)-one (anhydrate) as a light yellow solid.

Provenance & Evidence