Ammonia → 9-Bromo-4,5-dihydrobenzo[b]pyrazolo[1,5-d][1,4]oxazepine-2-carboxamide

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Reaction Conditions

Reaction Steps

A suspension of ethyl 9-bromo-4,5-dihydrobenzo[b]pyrazolo[1,5-d][1,4]oxazepine-2-carboxylate (compound 61-4, page 196, WO 2011/036280) (0.3 g, 0.89 mmol) in 7 M ammonia solution (in methanol, 4 ml) was heated in a microwave apparatus to 120-125° C. for 2.5 hours. After cooling the mixture was left at room temperature for 18 hours before the solvent was removed in vacuo and the residue was then taken up in tetrahydrofuran and pre-absorbed onto a small amount of silica. Purification by FCC (silica, 20-100% ethyl acetate in heptane) gave 245 mg (89%) of the title compound. 1H NMR (250 MHz, DMSO-d6) 8 ppm 3.18 (2H, t, J=5.79 Hz), 4.46 (2H, t, J=5.79 Hz), 6.71 (1H, s), 7.18 (1H, dd, J=8.60, 0.69 Hz), 7.39 (1H, br, s.), 7.51 (1H, ddd, J=8.68, 2.44, 0.76 Hz), 7.84 (1H, br. s.), 8.19 (1H, dd, J=2.44, 0.76 Hz)); M+1=308/310.

Provenance & Evidence