Amino-thienopyrimidine Series

 

This reaction is a repeat of JRC 32-2, and JRC 32-1, albeit using a microwave reactor and a bromine at the 6-position instead of an iodine.



4-(6-Bromothieno[3,2-d]pyrimidin-4-yl)morpholine (112.3 mg, 0.374 mmol, 1 eq.), 3-sulfamoylbenzene boronic acid, pinacol ester (37.7 mg, 0.13 mmol, 0.34 eq.) and AcOK (44 mg, 0.448 mmol, 1.1 eq.) were dissolved in 3 mL dioxane/H2O (degassed with argon). To this solution was added PdCl2(dtbpf) (6.3 mg, 0.11 mmol, 2.4 mol %). The solution was heated and stirred in a microwave reactor for 15 min at 150 °C at 150W. The solution was allowed to cool to rt.

NOTE: INCORRECT QUANTITIES USED.

TLC shows some starting material remaining, and several new products formed - all within a narrow rf band (0.3-0.4 in 10% MeOH/DCM). Crude reaction mixture purified via flash chromatography using DCM -> 10% MeOH/DCM as the eluent. Four pure fractions collected, though most mass remains in unisolated, non-pure fractions.

F1: 1% MeOH/DCM

F2: 2% MeOH/DCM

F3: 5% MeOH/DCM

F4: 10% MeOH/DCM


None of these fractions containes the desired product by NMR. This is confusing because F3, by mass spec, showed a minor peak corresponding to the desired product: