Hydroxyamine hydrochloride → 4-(6-Amino-pyridin-2-yloxy)-2-methyl-piperidine-1-carboxylic acid tert-butyl ester

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Reaction Steps

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).

Provenance & Evidence