Acetic Acid → tert-Butyl 7-[(5-methoxypyridin-2-yl)acetyl]-2,7-diazaspiro[3.5]nonane-2-carboxylate

Participants

Reaction Steps

In an oven dried round-bottomed flask was suspended tert-butyl 2,7-diazaspiro[3.5]nonane-2-carboxylate hydrochloride (1.89 g, 7.18 mmol) in anhydrous dichloromethane (50 mL). Triethylamine (2 mL, 14.4 mmol) followed by 5-methoxypyridin-2-yl)acetic acid (SM-1aa, 1.2 g, 7.18 mmol) were added. HATU (3.28 g, 8.62 mmol) was added and the resulting bright yellow solution was stirred at room temperature for 15 hours. The reaction mixture was washed consecutively with saturated aqueous sodium bicarbonate, water and brine and was dried over anhydrous MgSO4. Filtration and solvent removal afforded the crude material as a brownish oil (4.8 g). The product was purified by silica chromatography using a Combiflash ISCO (Teledyne Isco Inc., Lincoln, Nebr.) system to give the title compound (2-1a) as a light yellow foam (2.57 g, 96%). MS (ES+) 376.4 (M+H)+. 1H NMR (CDCl3) δ 1.42 (s, 9H), 1.57-1.61 (m, 2H), 1.65-1.69 (m, 2H), 3.47-3.54 (m, 4H), 3.58-3.64 (m, 4H), 3.83 (s, 3H), 3.85 (s, 2H), 7.15-7.18 (m, 1H), 7.23-7.26 (m, 1H), 8.18 (d, 1H).

Provenance & Evidence