Water → 4-Amino-8-bromo-N-butyl-cinnoline-3-carboxamide

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of 2-[(2-bromophenyl)-hydrazono]-N-butyl-2-cyanoacetamide (2.5 g, 7.7 mmol) in anhydrous toluene (Aldrich, 50 mL) under N2 was added portion-wise aluminum chloride (Aldrich, 3.1 g, 23.2 mmol) over 5 minutes. The mixture was heated to 90° C. with vigorous stirring for 1.5 hours then cooled to ˜0° C. Water (3 mL) was added drop wise followed by careful addition of Rochelle's salt (saturated aqueous potassium sodium tart rate, 50 mL). The reaction was stirred for 25 minutes and then poured into a separator funnel. The aqueous layer contained a thick white precipitate and was quickly removed. The organic layer was washed with Rochelle's salt and brine, dried over magnesium sulfate, filtered and concentrated to give 2.6 g slightly crude product which was purified on silica gel using a gradient of 20 to 60% ethyl acetate in hexane. Recrystallization from ethyl acetate/hexanes (10 mL each, 0° C. overnight) afforded the title compound as a white solid (650 mg, 26%). 1H NMR (300.132 MHz, CDCl3) δ 8.55 (bs, 1H), 8.13 (dd, J=7.4, 1.0 Hz, 1H), 7.82 (dd, J=8.5, 1.0 Hz, 1H), 7.50 (dd, J=8.5, 7.6 Hz, 1H), 3.52 (q, J=6.6 Hz, 2H), 1.65 (quintet, J=7.2 Hz, 2H), 1.47 (sextet, J=7.3 Hz, 2H), 0.97 (t, J=7.3 Hz, 3H). MS APCI, m/z=323/325 (M+H). HPLC 1.93 min.

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