A mixture of 4-chloro-9H-pyrimido[4,5-b]indole-7-carboxylic acid methyl ester (231 mg, 0.88 mmol), tert-butyl morpholin-2-yl-methylcarbamate (382 mg, 1.77 mmol), and triethylamine (246 μL, 1.77 mmol) in NMP was irradiated in a microwave at 140° C. for 15 minutes. An additional 246 μL of triethylamine was added to the reaction mixture and the irradiation repeated. The reaction mixture was then added to 5 mL water and the resulting precipitate was collected by filtration and purified by flash chromatography to give the title compound (39 mg, 0.088 mmol). LC-MS (2) Rt 2.67 min; m/z (ES+) 442.
