Methyl 5-nitroisoquinoline-3-carboxylate → Methyl 5-aminoisoquinoline-3-carboxylate

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Reaction Steps

The product of Example 71A (10.33 g, 44.5 mmol) in acetic acid/water (3/1) (320 mL) was treated with iron powder (5.06 g, 90.7 mmol). After stirring for 16 hours at room temperature, the reaction mixture was filtered the filtrate concentrated under reduced pressure to approximately half the original volume. The mixture was then extracted with dichloromethane (3×200 mL). The organic fractions were combined, dried (MgSO4), and the filtrate concentrated under reduced pressure to afford crude material. A precipitate formed in the aqueous phase after sitting for several hours. This was filtered to afford additional crude material. The crude material was purified by column chromatography (2% methanol/CH2Cl2) to provide the title compound. MS (ESI+) m/z 203 (M+H)+; MS (ESI−) m/z 201 (M−H)−; 1H NMR (DMSO-d6, 300 MHz) δ 3.92 (s, 3H), 6.34 (s, 2H), 6.96 (dd, J 1.0, 7.8, 1H), 7.31 (d, J 8.1, 1H), 7.51 (t, J 7.9, 1H), 8.82 (s, 1H), 9.15 (s, 1H); Anal. Calcd for C11H10N2O2: C, 65.34; H, 4.99; N, 13.85. Found: C, 65.03; H, 4.95; N, 13.65.

Provenance & Evidence