tert-Butyl methylcarbamate → tert-butyl N-methyl-N-[6-(2-morpholin-4-yl-4-oxochromen-8-yl)dibenzothiophen-2-yl]carbamate

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A solution of tert-butyl methylcarbamate (341 mg, 2.60 mmol) in dioxane (17.300 ml) was added to a stirred mixture of 6-(2-morpholino-4-oxo-4H-chromen-8-yl)dibenzo[b,d]thiophen-2-yl trifluoromethanesulfonate (974 mg, 1.73 mmol), TRIS(DIBENZYLIDENEACETONE)DIPALLADIUM(0) (39.7 mg, 0.04 mmol), (9,9-dimethyl-9H-xanthene-4,5-diyl)bis(diphenylphosphine) (50.2 mg, 0.09 mmol) and cesium carbonate (2261 mg, 6.94 mmol). The resulting mixture was stirred under nitrogen at 110 °C for 18 hours. The reaction mixture was poured into water (100 mL) and EtOAc (100 mL). Methanol addition was required to aid separation of layers. **[would vac off dioxane in future]**. The aqueous was further extracted with EtOAc (2 x 50 mL) and DCM (50 mL), all with the aid of methanol for layer separation. The combined organics were washed with saturated brine solution (still formed emulsions), dried over MgSO4 and concentrated under reduced pressure. The crude product was purified by flash silica chromatography, elution gradient 0 to 4% 7M NH3/MeOH in DCM. Pure fractions were evaporated to dryness to afford tert-butyl methyl(6-(2-morpholino-4-oxo-4H-chromen-8-yl)dibenzo[b,d]thiophen-2-yl)carbamate (630 mg, 66.9 %) as a yellow solid. This was taken through to the next step at 85% pure, with no further purification.

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