2-Thiophenecarbonyl chloride → HCID 11202878, compound

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Reaction Steps

2-Thiophene carbonyl chloride (0.16 mL, 1.5 mmol) was added to a stirred solution of 1-benzyl-2-oxo-4-piperazin-1-yl-1,2-dihydro-[1,8]-naphthyridine-3-carboxylic acid ethyl ester (5) (392 mg, 1 mmol) in pyridine (5 mL) at 0° C. under inert atmosphere. The solution was allowed to come at room temperature and further stirred for 18 h. The solution was poured into ice water, the solids formed were filtered, washed by water, dried, and recrystallized by ether and ethyl acetate to yield 256 mg (51%) of 1-benzyl-4-[4-(thiophene-2-carbonyl)-piperazin-1-yl]-2-oxo-1,2-dihydro-[1,8]-naphthyridine-3-carboxylic acid ethyl ester (6) as white solids. MP: 168° C.; 1H-NMR (DMSO-d6): δ 1.29 (t, J=6.9 Hz, 3H), 3.16 (m, 4H), 3.88 (m, 4H), 4.31 (q, J=6.9 Hz, 2H), 5.56 (s, 2H), 7.15 (dd, J=3.5, 4.9 Hz, 1H), 7.20-7.29 (m, 5H), 7.38 (dd, J=4.6, 8.2 Hz, 1H), 7.97 (d, J=4.9 Hz, 1H), 8.35 (dd, J=1.5, 7.5 Hz, 1H), 8.66 (dd, J=1.5, 7.5 Hz, 1H); EIMS: 503 (M+1), 525 (M+23). Anal. C27H26N4O4S (C,H,N).

Provenance & Evidence