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

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Reaction Steps

N-(8-Nitroquinolin-4-yl)-N-(N,N-dimethylaminoethyl)-2-iodo-5,6-dimethoxybenzamide (8a). Oxalyl chloride (762 mg, 6.0 mmol) was added to a solution of 3,4-dimethoxy-6-iodobenzoic acid (570 mg, 1.85 mmol) in anhydrous methylene chloride (20 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 7a (400 mg, 1.54 mmol) and triethylamine (1.14 g, 11.3 mmol) in methylene chloride (20 mL), and the resulting mixture was stirred at reflux overnight. 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 722 mg of the amide, in 85% yield; 1H NMR (CDCl3) δ 2.30 (s, 6H), 2.69 (m, 2H), 3.32 (s, 3H), 3.74 (s, 3H), 3.95 (m, 1H), 4.57 (m, 1H), 6.41 (s, 1H), 7.02 (s, 1H), 7.75 (m, 2H), 8.05 (d, 1H, J=6.6), 8.44 (d, 1H, J=8.4), 8.95 (d, 1H, J=4.4); 13C NMR (CDCl3) δ 45.4, 47.3, 55.7, 56.1, 56.5, 82.7, 110.7, 121.9, 123.3, 124.0, 126.1, 126.9, 127.2, 133.1, 140.9, 147.4, 148.4, 149.0, 150.1, 153.0, 169.9; IR (CHCl3) 1362, 1536, 1655.

Provenance & Evidence