Triethylamine → 8,9-Dimethoxy-2-nitro-5-[2-(N,N-dimethylamino)ethyl]-5H-dibenzo[c,h][1,6]naphthyridin-6-one

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Reaction Steps

N-(7-Nitroquinolin-4-yl)-N-(N,N-dimethylaminoethyl)-2-iodo-5,6-dimethoxybenzamide (8b). Oxalyl chloride (1.5 mg, 12.0 mmol) was added to a solution of 3,4-dimethoxy-6-iodobenzoic acid (985 mg, 3.2 mmol) in anhydrous methylene chloride (30 mL), and the stirred mixture was refluxed for 3 hours. The mixture was then concentrated to dryness under reduced pressure. The acid chloride was redissolved in 20 mL of anhydrous methylene chloride, and this solution was added to a solution of 7b (680 mg, 2.6 mmol) and triethylamine (2.0 g, 20.0 mmol) in methylene chloride (30 mL), and the resulting mixture was stirred at reflux for 2 hours. The reaction mix was cooled and washed with saturated sodium bicarbonate (3×75 mL), and extracted with 5% aqueous HCl (4×100 mL). The combined aqueous extracts were basified with 30% NaOH and then extracted with chloroform (3×100 mL). Combined organic extracts were then dried (MgSO4) and evaporated to give 760 mg of the amide, in 53% yield; 1H NMR (CDCl3) δ 2.23 (s, 6H), 2.63 (m, 2H), 3.28 (s, 3H), 3.73 (s, 3H), 3.92 (m, 1H), 4.50 (m, 1H), 6.33 (s, 1H), 7.02 (s, 1H), 7.73 (d, 1H, J=4.8), 8.41 (m, 2H), 8.98 (m, 2H); 13C NMR (CDCl3) δ 45.5, 47.5, 55.6, 56.1, 56.8, 82.9, 110.4, 120.6, 121.8, 124.1, 125.4, 126.6, 129.2, 133.3, 147.5, 148.4, 148.8, 149.9, 152.6, 153.1, 169.7; IR (CHCl3) 1345, 1536, 1655.

Provenance & Evidence