2H-pyran-3,5(4H,6H)-dione → 4-(2,1,3-benzoxadiazol-5-yl)-1-methyl-4,9-dihydro-1H-isoxazolo [3,4-b]pyrano[4,3-e]pyridine-3,5(6H,8H)-dione

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Reaction Steps

The product from Example 45A (0.11 g, 1 mmol), 2,1,3-benzoxadiazole-5-carboxaldehyde(0.15 g, 1 mmol), prepared as described in (Gasco, A. M., Ermondi, G. Eur. J. Med. Chem., (1996) 31, 3)and 2H-pyran-3,5(4H,6H)-dione (0.11 g, 1 mmol) were heated in 2 mL of ethanol for 2 days. The resulting mixture was allowed to cool to ambient temperature and filtered to provide the title compound as the filter cake (0.09 g). 1H NMR (300 MHz, DMSO-d6) δ 3.28 (s, 3H), 4.08 (s, 2H), 4.6 (q, 2H), 4.92 (s, 1H), 7.62 (dd, 1H), 7.76 (s, 1H), 8.0 (dd, 1H), 10.8 (s, 1H); MS (ESI) m/z 339 (M−H)−; Anal. Calcd for C16H12N4O5: C, 56.47; H, 3.52; N, 16.47. Found: C, 56.03;H, 3.97; N, 15.57.

Provenance & Evidence