反应详情

To a solution of tert-butyl 7-[(5-methoxypyridin-2-yl)acetyl]-2,7-diazaspiro[3.5]nonane-2-carboxylate (2-1a, 2.57 g, 6.85 mmol) in dioxane (5 mL) was added 4N HCl in dioxane (1.72 mL). The mixture was stirred at room temperature for 5 hours and heated at 45° C. overnight. The light-yellow mixture was concentrated to give a light-yellow sticky foam. The residue was suspended in ethyl acetate and evaporated to dryness (3×) to afford the title compound (2-1b, 1.86 g, 78%) MS (ES+) 276.4 (M+H)+. 1H NMR (CD3OD) δ 2.17-2.42 (m, 2H), 2.48 (d, 2H), 3.94-4.13 (m, 4H), 4.40 (d, 4H), 4.51 (s, 3H), 4.74 (s, 2H), 8.34 (d, 1H), 8.61-8.64 (m, 1H), 8.99-9.01 (m 1H).

1. temperatureheated at 45° C. overnight
2. concentrationThe light-yellow mixture was concentrated
3. customto give a light-yellow sticky foam
4. customevaporated to dryness (3×)