Potassium Iodide → ethyl (10R,15S)-3-oxo-1,4,12-triazatetracyclo[7.6.1.05,16.010,15]hexadeca-5,7,9(16)-triene-12-carboxylate

Participants

Reaction Conditions

Reaction Steps

Alternative to Example 5 above, (6bR,10aS)-ethyl 3,6b,9,10,10a-hexahydro-3-methyl-2-oxo-1H-pyrido[3′,4′:4,5]-pyrrolo[1,2,3-de]quinoxaline-8-carboxylate may also be made in a one pot method starting from Compound of Formula 1D. A 2 liter 4 neck round bottom flask is equipped with a mechanical stirrer, reflux condenser, N2 inlet, teflon covered K-type temperature probe with a controller, and a heating mantle. To the flask is charged (4aS,9bR)-ethyl 6-bromo-3,4,4a,5-tetrahydro-1H-pyrido[4,3-b]indole-2(9bH)-carboxylate (250 g, 769 mmol), chloroacetamide (124 g, 1153 mmol, 1.5 equiv), potassium iodide (191.5 g, 1160 mmol, 1.5 equiv), diisopropyl ethylamine (266 mL, 1531 mmol, 2.0 equiv), and dioxane (625 mL). The reaction is heated to reflux temperature of about 103° C. until less than 3% of the starting substrate is observed by HPLC (about 48 hours). Additional charge of N-methyl chloroacetamide and diisopropyl ethylamine maybe necessary. The reaction is then cooled to ca. 80° C., and at this temperature copper iodide (29.2 g, 153.8 mmol, 0.2 equiv), potassium carbonate (232.5 g, 1682 mmol, 2.2 equiv), dimethylethylene diamine (49.6 mL, 461 mmol, 0.6 equiv), and additional dioxane (375 mL) is added. The reaction is then re-heated to reflux and is monitored by HPLC. Reflux occurs at ca. 103° C. The reaction is monitored by HPLC.

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