N,N'-Dimethylethylenediamine → 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 Steps

A suspension of [4aS,9bR]-ethyl 5-(2-amino-2-oxoethyl)-6-bromo-3,4,4a,5-tetrahydro-1H-pyrido[4,3-b]indole-2(9bH)-carboxylate (254 mg, 1.34 mmol), cuprous iodide (254 mg, 1.34 mol), potassium carbonate (3.96 g, 28.7 mmol) and N,N′-dimethylethylenediamine (0.31 mL, 2.87 mmol) in dioxane (20 mL) is heated at reflux for 4.5 hours. Another portion of cuprous iodide (250 mg, 1.32 mmol) and N,N′-dimethylethylenediamine (0.33 mL, 3.05 mmol) is added. The resulting mixture is heated to a reflux for another 3 hours and then at 73° C. for about 66 hours. The reaction mixture is concentrated and passed through a short alumina column using 100:3:3 dichloromethan:triethylamine:methanol. The resulting solvent from the column is evaporated to a solid and redissolved in dichloromethane. The dichloromethane solution is washed with brine, dried with sodium phosphate and concentrated to a solid (3.7 g, 95%, 83% pure by HPLC).

Provenance & Evidence