Hydrochloric Acid → Hydrochloric Acid

Participants

Reaction Steps

To a solution of 1-(pyrazin-2-yl)-2-(thiophen-3-yl)ethanone (Intermediate 66) (30 mg, 0.15 mmol), 3-ethoxy-4-hydroxy-5-nitrobenzaldehyde (31 mg, 0.15 mmol) and urea (27 mg, 0.45 mmol) in 2 mL of ethanol was added 0.2 mL of conc. HCl, and was stirred at reflux overnight. The mixture was cooled and then purified by preparative HPLC (30-60% acetonitrile+0.15% trifluoroacetic acid in water, over 15 min.), the desired eluting solution was treated with HCl/MeOH (2 mL, 2M) and concentrated in vacuo to give Compound 131 as HCl salt (8.3 mg, yield 12.3%). 1H NMR (CD3OD 400 MHz): δ 8.69 (dd, J=1.6 Hz, 2.4 Hz, 1H), 8.48 (d, J=3.6 Hz, 1H), 8.17 (d, J=1.6 Hz, 1H), 7.60 (d, J=2.0 Hz, 1H), 7.37 (dd, J=3.2 Hz, 5.2 Hz, 1H), 7.18 (d, J=2.0 Hz, 1H), 7.02 (dd, J=1.2 Hz, 2.8 Hz, 1H), 6.66 (dd, J=1.2 Hz, 5.2 Hz, 1H), 5.42 (s, 1H), 4.11-4.06 (m, 2H), 1.42 (t, J=7.2 Hz, 3H); MS (ESI): m/z 440.2 [M+1]+.

Provenance & Evidence