Triethylamine → 2-(2',5'-Dimethoxybenzoyl)-1-methylene-5,6,7-trimethoxy-1,2,3,4-tetrahydroisoquinoline

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Reaction Steps

A solution of compound 45 (746 mg, 3.7 mmol) in anhydrous benzene (2 mL) was slowly added at room temperature to a solution of compound 44 (880 mg, 3.7 mmol) in anhydrous benzene (10 mL) containing triethylamine (568 mg, 5.6 mmol, 0.78 mL). The resulting solution was heated at reflux with stirring under Ar for 2 h. White NH4Cl precipitated and was removed by filtration. The filtrate was evaporated to dryness and the residue was subjected to flash chromatography (ether:triethylamine, 99:1 by volume, silica gel 230-300 mesh) to give compound 46 as an oil (1.3 g, 87.8%): 1H NMR (CDCl3, 200 MHz) δ6.87 (s, 1H), 6.85 (d, 1H, J=10 Hz), 6.80 (d, 1H, J=3 Hz), 6.70 (d, 1H, J=10 Hz), 5.21 (s, br 1H), 4.55 (s, br, 1H), 3.90 (s, 6H), 3.88 (s, 3H), 3.84 (s, 3H), 3.75 (s, 3H), 3.41 (s, br, 2H), 2.88 (t, 2H, J=6 Hz). CIMS (isobutane) m/e 400 (MH+, 100).

Provenance & Evidence