Hydrochloric Acid → Hydrochloric Acid

Participants

Reaction Steps

A mixture of 1-(pyridin-4-yl)-2-(thiophen-3-yl)ethanone (Intermediate 70) (180 mg, 0.89 mmol), 3-ethoxy-4-hydroxy-5-nitrobenzaldehyde (188 mg, 0.89 mmol), urea (160 mg, 2.70 mmol), conc. hydrochloric acid (0.5 mL) in ethanol (3 mL) was refluxed for 45 hours. The mixture was concentrated and purified by prep-HPLC (0.1% TFA as additive). To the residue was added HCl/MeOH (2 mL, 2 N) and concentrated to give Compound 136 as HCl salt (24.3 mg, yield 6%). 1HNMR (DMSO-d6 400 MHZ): δ 10.31 (brs, 1H), 9.03 (s, 1H), 8.72 (d, J=6.4 Hz, 2H), 7.71 (s, 1H), 7.61 (d, J=6.0 Hz, 2H), 7.45 (d, J=2.0 Hz, 1H), 7.30 (dd, J=4.8, 2.8 Hz, 1H), 7.17 (d, J=1.6 Hz, 1H), 7.02 (dd, J=2.8, 1.2 Hz, 1H), 6.50 (dd, J=5.2, 1.2 Hz, 1H), 5.32 (d, J=2.4 Hz, 1H), 4.05 (q, J=6.8 Hz, 2H), 1.34 (t, J=6.8 Hz, 3H). MS (ESI): m/z 438.9 [M+H]+.

Provenance & Evidence