反应详情

Combine 4-[6-(benzhydrylidene-amino)-pyridin-2-yloxy]-2-methyl-piperidine-1-carboxylic acid tert-butyl ester cis isomer 1 (preparation 61), methanol (150 mL), sodium acetate (2.54 g, 30.94 mmol), and hydroxylamine monohydrogen chloride (1.61 g, 23.2 mmol) and stir. After 30 min., partition between 0.25 M sodium hydroxide solution (100 mL) and 1:1 hexane:ethyl acetate (300 mL). Combine organic layers, wash with aqueous NaCl solution, dry over sodium sulfate, filter and concentrate. Purify the residue by silica gel flash chromatography eluting with 9:1:0.2 hexane:ethyl acetate:2M ammonia/methanol to obtain the title compound (2.81 g, 70%). 1H NMR (CDCl3): 7.3 (dd, 1H), 6.05 (m, 2H), 5.3 (m, 1H), 4.3 (m, 1H), 4.25 (bs, 2H), 3.85 (m, 1H), 3.25 (m, 1H), 1.9 (m, 3H), 1.7 (m, 1H), 1.5 (s, 9H), 1.3 (d, 3H).

1. custompartition between 0.25 M sodium hydroxide solution (100 mL) and 1:1 hexane
2. washCombine organic layers, wash with aqueous NaCl solution
3. dry with materialdry over sodium sulfate
4. filtrationfilter
5. concentrationconcentrate
6. customPurify the residue by silica gel flash chromatography
7. washeluting with 9:1:0.2 hexane