反应详情

A mixture of 1-benzyl-4-[N-propyl-N-(3-nitro-2-pyridinyl)amino]piperidine (EXAMPLE 113, 2.61 g) in aqueous titanium (III) chloride (30 ml, 19 wt % in 20% aqueous hydrochloric acid) is stirred under reduced pressure for 18 hrs and then added to concentrated aqueous ammonium hydroxide (250 ml), and the resulting mixture is extracted with methylene chloride (4×100 ml). The combined organic phase is washed with saline (50 ml), dried over sodium sulfate, and concentrated under reduced pressure to give the crude product which is then chromatographed (silica gel, 230-400 mesh, 150 g; eluting with a gradient of methanol/methylene chloride (2.5/97.5-5/95)) to give the title compound, mp=73°-74°.

1. extractionthe resulting mixture is extracted with methylene chloride (4×100 ml)
2. washThe combined organic phase is washed with saline (50 ml)
3. dry with materialdried over sodium sulfate
4. concentrationconcentrated under reduced pressure
5. customto give the crude product which
6. customis then chromatographed (silica gel, 230-400 mesh, 150 g
7. washeluting with a gradient of methanol/methylene chloride (2.5/97.5-5/95))